Document:

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                                                                   Exhibit 10.18

                                 LEASE AGREEMENT

     THIS LEASE AGREEMENT is made this 24 day of Feb., 2000, between
ARE-ONE INNOVATION DRIVE, LLC, a Delaware limited liability company
("Landlord"), and t.Breeders, Inc., a Delaware corporation ("Tenant").

Address:    One Innovation Drive, Worcester, Massachusetts

Premises:   That portion of the Project, containing approximately 12,254
            rentable square feet, as determined by Landlord, as shown on Exhibit
            A.

Project:    The real property on which the building in which the Premises are
            located, together with all improvements thereon and appurtenances
            thereto as described on Exhibit B.

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<S>                                         <C>
Base Rent:  $18,636.30, per month          Rentable Area of Premises: 12,254 sq.ft

Rentable Area of Project:  115,179 sq. ft.  Tenant's Share of Operating
                                            Expenses: 10.64%

Security Deposit:  $161,818.00            Target Commencement Date: February
                                            1, 2000

Rent Adjustment Percentage:                 Greater of 3% or the CPI Adjustment
                                            Percentage, not to exceed 7%.
</Table>

Base Term:  60 months from the first day of the month following the month in
            which the Commencement Date occurs.

Permitted Use:     Research and development laboratory, related office and other
                   related uses.

Address for Rent Payment:                    Landlord's Notice Address:
135 N. Los Robles Avenue, Suite 250          135 N. Los Robles Avenue, Suite 250
Pasadena, CA 91101                           Pasadena, CA 91101
Attention: Accounts Receivable               Attention: General Counsel

Tenant's Notice Address:
t.Breeders, Inc.
One Innovation Drive
Worcester, MA 01605
Attention:    Mr. Morey Kraus

     The following Exhibits and Addenda are attached hereto and incorporated
herein by this reference:

/X/  EXHIBIT A - PREMISES DESCRIPTION    /X/  EXHIBIT B - DESCRIPTION OF PROJECT
/X/  EXHIBIT C - WORK LETTER             /X/  EXHIBIT D - COMMENCEMENT DATE
/X/  EXHIBIT E - RULES AND REGULATIONS   /X/  EXHIBIT F - TENANT'S PERSONAL
                                                          PROPERTY

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/X/  EXHIBIT G - ESTOPPEL CERTIFICATE    /X/  EXHIBIT H - NONDISTURBANCE
                                                          AGREEMENT

     1. LEASE OF PREMISES. Upon and subject to all of the terms and conditions
hereof, Landlord hereby leases the Premises to Tenant and Tenant hereby leases
the Premises from Landlord. The portions of the Project which are for the
non-exclusive use of tenants of the Project are collectively referred to herein
as the "COMMON AREAS." Landlord reserves the right to modify Common Areas,
provided that such modification do not materially adversely affect Tenant's use
of the parking area or Tenant's use of the Premises for the Permitted Use.

     2. DELIVERY; ACCEPTANCE OF PREMISES; COMMENCEMENT DATE. Landlord shall use
reasonable efforts to deliver the Premises to Tenant on or before the Target
Commencement Date ("Delivery" or "Deliver"). if Landlord fails to timely Deliver
the Premises, Landlord shall not be liable to Tenant for any loss or damage
resulting therefrom, and this Lease shall not be void or voidable except as
provided herein. If Landlord does not Deliver the Premises within 60 days of the
Target Commencement Date for any reason other than Force Majeure Delays or the
failure of the existing tenant, Massachusetts Biomedical Institute, Inc.
("MBI"), to vacate the Premises, this Lease shall be voidable by Landlord or
Tenant by written notice to the other, and if so voided by either: (a) so long
as Tenant is not in default hereunder, the Security Deposit shall be returned to
Tenant, and (b} neither Landlord nor Tenant shall have any further rights,
duties or obligations under this Lease, except with respect to provisions which
expressly survive termination of this Lease. If neither Landlord nor Tenant
elects to void this Lease within 5 business days of the lapse of such 60 day
period, such right to void this Lease shall be waived and this Lease shall
remain in full force and effect.

     The "COMMENCEMENT DATE" shall be the date Landlord Delivers the Premises to
Tenant. Upon request of Landlord, Tenant shall execute and deliver a written
acknowledgment of the Commencement Date and the expiration date of the Term when
such are established in the form attached to this Lease as Exhibit D; PROVIDED,
HOWEVER, Tenant's failure to execute and deliver such acknowledgment shall not
affect Landlord's rights hereunder. The "Term" of this Lease shall be the Base
Term and the Extension Term which Tenant may elect pursuant to Section 40
hereof.

     Except as set forth in the Work Letter, if applicable: (i) Tenant shall
accept the Premises in their condition as of the Commencement Date, subject to
all applicable laws, ordinances, regulations, covenants and restrictions; (ii)
Landlord shall have no obligation for any defects in the Premises; and (ii)
Tenant's taking possession of the Premises shall be conclusive evidence that
Tenant accepts the Premises and that the Premises were in good condition at the
time possession was taken. Any occupancy of the Premises by Tenant before the
Commencement Date shall be subject to all of the terms and conditions of this
Lease.

     Tenant acknowledges and agrees that Tenant's use and occupancy of the
Premises may be severely and adversely impacted by Landlord's Work and Tenant
shall not be entitled and waives any claim to any abatement of rent or any other
concession as a result of any such adverse impact.

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     Tenant agrees and acknowledges that neither Landlord nor any agent of
Landlord has made any representation or warranty with respect to the condition
of any or all of the Premises or the Project, and/or the suitability of the
Premises or the Project for the conduct of Tenant's business, and Tenant waives
any implied warranty that the Premises or the Project are suitable for the
Permitted Use. This Lease including all exhibits hereto constitutes the complete
agreement of Landlord and Tenant with respect to the subject matter hereof and
supersedes any and all prior representations, inducements, promises, agreements,
understandings and negotiations which are not contained herein. Landlord in
executing this Lease does so in reliance upon Tenant's representations,
warranties, acknowledgments and agreements contained herein.

     Tenant hereby acknowledges and agrees that the Premises is currently
subject to a lease with MBI ("EXISTING LEASE") and that a portion of the
Premises may be subject to the prior rights of other tenants of the Project.
This Lease and Landlord's obligations hereunder shall be subject to (i) the
release or expiration of any prior rights of any other tenant of the Project
pursuant to such tenant's lease in and to any portion of the Premises, and (ii)
Landlord's receipt of a fully executed termination agreement with respect to the
Existing Lease and the vacation of the Premises by MBI.

     3. Rent.

     (a) BASE RENT. The first month's Base Rent, as adjusted pursuant to Section
4 hereof, and the Security Deposit shall be due and payable on delivery of an
executed copy of this Lease to Landlord. Tenant shall pay to Landlord in
advance, without demand, abatement, deduction or set-off, monthly installments
of Base Rent on or before the first day of each calendar month during the Term
hereof, in lawful money of the United States of America, at the office of
Landlord for payment of Rent set forth above, or to such other person or at such
other place as Landlord may from time designate in writing. Payments of Base
Rent for any fractional calendar month shall be prorated and paid on the basis
of a 30 day month. The obligation of Tenant to pay Base Rent and other sums to
Landlord and the obligations of Landlord under this Lease are independent
obligations. Tenant shall have no right at any time to abate, reduce, or set-off
any Rent due hereunder except for any abatement as may be expressly provided in
this Lease.

     (b) ADDITIONAL RENT. In addition to Base Rent, Tenant agrees to pay to
Landlord as additional rent ("Additional Rent"): (i) Tenant's Share of
"Operating Expenses," and (ii) any and all other amounts Tenant assumes or
agrees to pay under the provisions of this Lease, including, without limitation,
any and all other sums that may become due by reason of any default of Tenant or
failure to comply with the agreements, terms, covenants and conditions of this
Lease to be performed by Tenant, after any applicable notice and cure period.

     4. BASE RENT ADJUSTMENTS.

     (a) ADJUSTMENT FOR TENANT IMPROVEMENTS. Upon Substantial Completion of
Landlord's Work ("RENT INCREASE DATE"), Base Rent shall be increased from
$18,636.30 to $26,969.63. As used herein, the term "FORCE MAJEURE DELAYS,"
"SUBSTANTIAL COMPLETION," and "Landlord's Work" shall have the meaning set forth
for such terms in the Work Letter.

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     (b) ANNUAL ADJUSTMENTS. Base Rent, as increased pursuant to Section 4(a),
shall be increased on each annual anniversary of the first day of the first full
month during the Term of this Lease by multiplying the Base Rent payable
immediately before such adjustment by the Rent Adjustment Percentage and adding
the resulting amount to the Base Rent payable immediately before such
adjustment. Base Rent, as so adjusted, shall thereafter be due as provided
herein. Base Rent adjustments for any fractional calendar month shall be
prorated. "CPI Adjustment Percentage" means a fraction, stated as a percentage,
the numerator of which shall be the Index for the calendar month 3 months before
the month in which the Base Rent adjustment is to be made, and the denominator
of which shall be the Index for the calendar month 3 months before the last Base
Rent adjustment or, if no prior Base Rent adjustment has been made; 3 months
before the first day of the first full month during the Term of this Lease.
Landlord shall give Tenant written notice indicating the Base Rent, as adjusted
pursuant to this Section, and the method of computation, and Tenant shall pay to
Landlord an amount equal to any underpayment of Base Rent by Tenant within
fifteen days of Landlord's notice to Tenant. "Index" means the "Consumer Price
Index-All Urban Consumers-Boston, Massachusetts Metropolitan Area" compiled by
the U.S. Department of Labor, Bureau of Labor Statistics, (1 982-84 = 100). If a
substantial change is made in the Index, the revised Index shall be used,
subject to such adjustments as Landlord may reasonably deem appropriate in order
to make the revised index comparable to the prior Index. If the Bureau of Labor
Statistics ceases to publish the Index, then the successor or most nearly
comparable index, as reasonably determined by Landlord, shall be used, subject
to such adjustments as Landlord may reasonably deem appropriate in order to make
the new index comparable to the Index.

     5. OPERATING EXPENSE PAYMENTS. Landlord shall deliver to Tenant a written
estimate of Operating Expenses for each calendar year during the Term (the
"ANNUAL ESTIMATE"), which may be reasonably revised by Landlord from time to
time during such calendar year. During each month of the Term, on the same date
that Base Rent is due, Tenant shall pay Landlord an amount equal to 1/1 2 of the
annual cost, as reasonably estimated by Landlord from time to time, of Tenant's
Share of Operating Expenses. Payments for any fractional calendar month shall be
prorated.

     The term "OPERATING EXPENSES" means all costs and expenses of any kind or
description whatsoever incurred or accrued by Landlord with respect to the
Project (including Taxes, reasonable reserves consistent with good business
practice for future repairs and replacements, capital repairs and improvements
amortized over the lesser of 7 years and the useful life of such capital items
and the costs of Landlord's third party property manager not to exceed 5% of
Base Rent or, if there is no third party property manager, administration rent
in the amount of 5.0% of Base Rent), excluding only:

     (a)  the original construction costs of the Project and renovation prior to
          the date of the Lease and costs of correcting defects in such original
          construction or renovation;

     (b)  completing, fixturing, improving, renovating, painting, redecorating
          or other work, which Landlord pays for or performs for specific
          tenants within their premises and costs of correcting defects in such
          work;

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     (c)  capital expenditures for expansion of the Project;

     (d)  interest, financing costs and amortization of funds borrowed by
          Landlord, whether secured or unsecured and all payments of base rent
          (but not taxes or operating expenses) under any superior ground lease;

     (e)  depreciation of the Project (except for capital improvements, the cost
          of which are includable in Operating Expenses and amortized as set
          forth above);

     (f)  advertising, legal and space planning expenses and leasing commissions
          and other costs and expenses incurred in procuring tenants for the
          Project, including any leasing office maintained in the Project;

     (g)  salaries, wages, benefits and other compensation paid to officers and
          employees of Landlord who are not assigned in whole or in part to the
          operation, management, maintenance or repair of the Project;

     (h)  costs of utilities outside normal business hours sold--to-tenants of
          the Project;

     (i)  any expenses otherwise includable within Operating Expenses to the
          extent actually reimbursed by persons other than tenants of the
          Project under leases for space in the Project;

     (j)  legal and other expenses incurred in the negotiation or enforcement of
          leases;

     (k)  costs relating to maintaining Landlord's existence, either as a
          corporation, partnership, or other entity;

     (l)  costs (including attorneys' fees and costs of settlement, judgments
          and payments in lieu thereof) arising from claims, disputes or
          potential disputes pertaining to Landlord, but not the Project, or
          from Landlord's failure to make any payment required to be made by
          Landlord hereunder before delinquency;

     (m)  costs incurred by Landlord due to the violation by Landlord, its
          employees, agents or contractors or any tenant of the terms and
          conditions of any lease of space in the Project or any Legal
          Requirement;

     (n)  tax penalties incurred as a result of Landlord's negligence, inability
          or unwillingness to make payment and/or to file any tax or
          informational returns when due;

     (o)  overhead and profit increment paid to the Landlord or to subsidiaries
          or affiliates of Landlord for goods and/or services in or to the
          Project to the extent the same exceeds the costs of such goods and/or
          services rendered by unaffiliated third parties on a competitive
          basis;

     (p)  costs arising from Landlord's charitable or political contributions or
          fine art maintained at the Project;

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     (q)  costs to be reimbursed by other tenants of the Project, whether or not
          actually paid;

     (r)  costs in connection with services (including electricity), items or
          other benefits of a type which are not standard for the Project and
          which are not available to Tenant without specific charges therefor,
          but which are provided to another tenant or occupant of the Project,
          whether or not such other tenant or occupant is specifically charged
          therefore by Landlord;

     (s)  costs incurred in the sale or refinancing of the Project; and

     (t)  net income, franchise, capital stock, estate or inheritance taxes.

     Within 90 days after the end of each calendar year, Landlord shall furnish
to Tenant a statement (an "ANNUAL STATEMENT") showing in reasonable detail: (a)
the total and Tenant's Share of actual Operating Expenses for the previous
calendar year, and (b) the total of Tenant's payments in respect of Operating
Expenses for such year. If Tenant's Share of actual Operating Expenses for such
year exceeds Tenant's payments of Operating Expenses for such year, the excess
shall be immediately due and payable by Tenant as Rent. If Tenant's payments of
Operating Expenses for such year exceed Tenant's Share of actual Operating
Expenses for such year Landlord shall, in its sole and absolute discretion,
either: (i) credit the excess amount to the next succeeding installments of
Operating Expenses due hereunder, or (ii) pay the excess to Tenant within 30
days after delivery of such Annual Statement, except that after expiration, or
earlier termination of the Term, Landlord shall pay the excess to Tenant after
deducting all other amounts due Landlord.

     The Annual Statement shall be final and binding upon Tenant unless Tenant,
within 30 days after Tenant's receipt thereof, shall contest any item therein by
giving written notice to Landlord, specifying each item contested and the reason
therefor. If, during such 30 day period, Tenant reasonably and in good faith
questions or contests the correctness of Landlord's statement of Tenant's Share
of Operating Expenses, Landlord will provide Tenant with access to Landlord's
books and records relating to the operation of the Project and such information
as Landlord reasonably determines to be responsive to Tenant's questions. If
after Tenant's review of such information, Landlord and Tenant cannot agree upon
the amount of Tenant's Share of Operating Expenses, then Tenant shall have the
right to have an independent public accounting firm acceptable to Landlord in
its sole and absolute discretion, hired by Tenant (at Tenant's sole cost and
expense) and approved by Landlord (which approval shall not be unreasonably
withheld or delayed), audit and/or review Landlord's books and records relating
to the operation of the Project and such other information relating to the
operation of the Project for the year in question (the "INDEPENDENT REVIEW").
The results of any such Independent Review shall be binding on Landlord and
Tenant. If the Independent Review shows that Tenant's pro rata share of the
Operating Expenses actually paid by Tenant for the calendar year in question
exceeded Tenant's obligations for such calendar year, Landlord shall at
Landlord's option either (i) credit the excess amount to the next succeeding
installments of estimated Operating Expenses or (ii) pay the excess to Tenant
within 30 days after delivery of such statement, except that after expiration or
earlier termination of the Term, Landlord shall pay the excess to Tenant after
deducting all other amounts due Landlord. If the Independent Review shows that
Tenant's payments of Tenant's

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Share of Operating Expenses for such calendar year were less than Tenant's
obligation for the calendar year, Tenant shall pay the deficiency to the
Landlord within 30 days after delivery of such statement. If the Independent
Review shows that Tenant has overpaid Tenant's pro rata share of Operating
Expenses by more than 5% then Landlord shall reimburse Tenant for all costs
incurred by Tenant for the Independent Review. Operating Expenses for the
calendar years in which Tenant's obligation to share therein begins and ends
shall be prorated. Not withstanding anything set forth herein to the contrary,
if the Project is not at least 95% occupied on average during any year of the
Term, Tenant's Share of Operating Expenses for such year shall be computed as
though the Project had been 95% occupied on average during such year.

     "TENANT'S SHARE" shall be the percentage set forth on the first page of
this Lease as Tenant's Share as reasonably adjusted by Landlord for changes in
the physical size of the Premises or the Project occurring thereafter. Landlord
may equitably increase Tenant's Share for any item of expense or cost
reimbursable by Tenant that relates to a repair, replacement, or service that
benefits only the Premises or only a portion of the Project that includes the
Premises or that varies with occupancy or use. Base Rent, Tenant's Share of
Operating Expenses and all other amounts payable by Tenant to Landlord hereunder
are collectively referred to herein as "RENT."

     6. SECURITY DEPOSIT. Tenant shall deposit with Landlord on the date
of this Lease security (the "SECURITY DEPOSIT") for the performance of all of
its obligations in the amount set forth in the Basic Lease Provisions, which
security shall be in the form of either cash or an unconditional and irrevocable
letter of credit (the "LETTER OF CREDIT"): (i) in form and substance
satisfactory to Landlord, (ii) naming Landlord as beneficiary, (iii) expressly
allowing Landlord to draw upon it at any time from time to time by delivering to
the issuer written notice that Landlord is entitled to draw thereunder, (iv)
drawable on an FDIC-insured financial institution satisfactory to Landlord, and
(v) redeemable in the state of Landlord's choice. If Tenant does not provide
Landlord with a substitute Letter of Credit complying with all of the
requirements hereof at least ten (10) days before the stated expiration date of
the then current Letter of Credit, Landlord shall have the right to draw upon
the current Letter of Credit and hold the funds drawn as the Security Deposit.
The Security Deposit shall be held by Landlord as security for the performance
of Tenant's obligations under this Lease. Upon each occurrence of a Default,
Landlord may use all or any part of the Security Deposit to pay delinquent
payments due under this Lease, and the cost of any damage, injury, expense or
liability caused by such Default, without prejudice to any other remedy provided
herein or provided by law. Tenant hereby waives the provisions of any law, now
or hereafter in force, which provide that Landlord may claim from a security
deposit only those sums reasonably necessary to remedy defaults in the payment
of Rent, to repair damage caused by Tenant or to clean the Premises, it being
agreed that Landlord may, in addition, claim those sums reasonably necessary to
compensate Landlord for any other loss or damage, foreseeable or unforeseeable,
caused by the act or omission of Tenant or any officer, employee, agent or
invitee of Tenant. Upon bankruptcy or other debtor-creditor proceedings against
Tenant, the Security Deposit shall be deemed to be applied first to the payment
of Rent and other charges due Landlord for periods prior to the filing of such
proceedings. Upon any such use of all or any portion of the Security Deposit,
Tenant shall, within five (5) days after demand from Landlord, reinstate the
Security Deposit to its original amount. If Tenant shall fully perform every
provision of this Lease to be performed by Tenant, the Security Deposit, or any
balance thereof, shall be returned to Tenant (or, at Landlord's

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option, to the last assignee of Tenant's interest hereunder) within 90 days
after the expiration or earlier termination of this Lease.

     If Landlord transfers its interest in the Project or this Lease, Landlord
shall either (a) upon written notice to Tenant (but without Tenant's consent),
transfer any Security Deposit then held by Landlord to a person or entity
assuming Landlord's obligations under this Section 6, or (b) return to Tenant
any Security Deposit then held by Landlord and remaining after the deductions
permitted herein. Upon such transfer to such transferee and the delivery of
notice to Tenant regarding such transfer or the return of the Security Deposit
to Tenant, Landlord shall have no further obligation with respect to the
Security Deposit, and Tenant's right to the return of the Security Deposit shall
apply solely against Landlord's transferee. The Security Deposit is not an
advance rental deposit or a measure of Landlord's damages in case of Tenant's
default. Landlord's obligation respecting the Security Deposit is that of a
debtor, not a trustee and no interest shall accrue thereon.

     7. USE. The Premises shall be used solely for the Permitted Use set
forth in the Basic Lease Provisions, in compliance with all laws, orders,
judgments, ordinances, regulations, codes, directives, permits, licenses,
covenants and restrictions now or hereafter applicable to the Premises, and the
use and occupancy thereof (collectively, "LEGAL REQUIREMENTS"). Tenant shall,
upon 5 days' written notice from Landlord, discontinue any use of the Premises
which is declared by any governmental authority having jurisdiction to be a
violation of any Legal Requirement. Tenant will not use or permit the Premises
to be used for any purpose or in any manner that would void Tenant's or
Landlord's insurance, increase the insurance risk, or cause the disallowance of
any sprinkler or other credits. Tenant shall reimburse Landlord promptly upon
demand for any additional premium charged for any such insurance policy by
reason of Tenant's failure to comply with the provisions of this Section or
otherwise caused by Tenant's use and/or occupancy of the Premises. Tenant will
use the Premises in a careful, safe and proper manner and will not commit waste,
overload the floor or structure of the Premises, subject the Premises to use
that would damage the Premises or obstruct or interfere with the rights of
Landlord or other tenants or occupants of the Project, including conducting or
giving notice of any auction, liquidation, or going out of business sale on the
Premises, or using or allowing the Premises to be used for any unlawful purpose.
Tenant shall cause any equipment or machinery to be installed in the Premises so
as to reasonably prevent sounds or vibrations therefrom from extending into
Common Areas, or other space in the Project. Tenant shall not place any
machinery or equipment weighing 500 pounds or more in or upon the Premises or
transport or move such items through the Common Areas of the Project or in the
Project elevators without the prior written consent of Landlord. Except as may
be provided under the Work Letter, Tenant shall not, without the prior written
consent of Landlord, use the Premises in any manner which will require
ventilation, air exchange, heating, gas, steam, electricity or water beyond the
existing capacity of the Project as proportionately allocated to the Premises
based upon Tenant's Share as usually furnished for the Permitted Use.

     Tenant, at its sole expense, shall make any alterations or modifications,
to the interior or the exterior of the Premises or the Project, that are
required by Legal Requirements (including, without limitation, compliance of the
Premises with the Americans With Disabilities Act, 42 U.S.C. Section 12101, et
seq. (together with regulations promulgated pursuant thereto, "ADA")) related to
Tenant's use or occupancy of the Premises. Landlord, as part of Operating
Expenses,

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shall be responsible for compliance of the Project (other than the Premises)
with ADA. Landlord shall not be responsible for ADA compliance of the Project to
the extent such compliance is related to or required by Tenant's use or
occupancy of the Premises. Notwithstanding any other provision herein to the
contrary, Tenant shall be responsible for any and all demands, claims,
liabilities, losses, costs, expenses, actions, causes of action, damages or
judgments, and all reasonable expenses incurred in investigating or resisting
the same (including, without limitation, reasonable attorneys' fees, charges and
disbursements and costs of suit) (collectively, "CLAIMS") arising out of or in
connection with Legal Requirements and Tenant shall indemnify, defend, hold and
save Landlord harmless from and against any and all Claims arising out of or in
connection with any failure of the Premises to comply with any Legal
Requirement.

     8. HOLDING OVER. If, with Landlord's express written consent, Tenant
retains possession of the Premises after the termination of the Term, (i) unless
otherwise agreed in such written consent, such possession shall be subject to
immediate termination by Landlord at any time, (ii) all of the other terms and
provisions of this Lease (including, without limitation, the adjustment of Base
Rent pursuant to Section 4 hereof) shall remain in full force and effect
(excluding any expansion or renewal option or other similar right or option)
during such holdover period, (iii) Tenant shall continue to pay Base Rent in the
amount payable upon the date of the expiration or earlier termination of this
Lease or such other amount as Landlord may indicate, in Landlord's sole and
absolute discretion, in such written consent, and (iv) all other payments shall
continue under the terms of this Lease. If Tenant remains in possession of the
Premises after the expiration or earlier termination of the Term without the
express written consent of Landlord, (A) Tenant shall become a tenant at
sufferance upon the terms of this Lease except that the monthly rental shall be
equal to 200% of the Rent in effect during the last 30 days of the Term, and (B)
Tenant shall be responsible for all damages suffered by Landlord resulting from
or occasioned by Tenant's holding over. No holding over by Tenant, whether with
or without consent of Landlord, shall operate to extend this Lease except as
otherwise expressly provided, and this Section 8 shall not be construed as
consent for Tenant to retain possession of the Premises. Acceptance by Landlord
of Rent after the expiration or earlier termination of the Term shall not result
in a renewal or reinstatement of this Lease.

     9. TAXES. Landlord shall pay, as part of Operating Expenses, all taxes,
levies, assessments and governmental charges of any kind (collectively referred
to as "TAXES") imposed by any federal, state, regional, municipal, local or
other governmental authority or agency, including, without limitation,
quasi-public agencies (collectively, "GOVERNMENTAL AUTHORITY") during the Term,
including, without limitation all Taxes: (i) imposed on or measured by or based,
in whole or in part, on rent payable to Landlord under this Lease and/or from
the rental by Landlord of the Project or any portion thereof, or (ii) based on
the square footage assessed value or other measure or evaluation of any kind of
the Premises or the Project, or (iii) assessed or imposed by or on the operation
or maintenance of any portion of the Premises or the Project, including parking,
or (iv) assessed or imposed by, or at the direction of, or resulting from
statutes or regulations, or interpretations thereof, promulgated by, any
Governmental Authority, or (v) imposed as a license or other fee on Landlord's
business of leasing space in the Project. Landlord may contest by appropriate
legal proceedings the amount, validity, or application of any Taxes or liens
securing Taxes. Taxes shall not include any net income taxes imposed on Landlord
unless such net income taxes are in substitution for any Taxes payable
hereunder. If any such Tax is levied or assessed directly against Tenant, then
Tenant shall be responsible for

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and shall pay the same at such times and in such manner as the taxing authority
shall require. Tenant shall pay, prior to delinquency, any and all Taxes levied
or assessed against any personal property or trade fixtures placed by Tenant in
the Premises, whether levied or assessed against Landlord or Tenant. If any
Taxes on Tenant's personal property or trade fixtures are levied against
Landlord or Landlord's property, or if the assessed valuation of the Project is
increased by a value attributable to improvements in or alterations to the
Premises, whether owned by Landlord or Tenant and whether or not affixed to the
real property so as to become a part thereof, higher than the base valuation on
which Landlord from time-to-time allocates Taxes to all tenants in the Project,
Landlord shall have the right, but not the obligation, to pay such Taxes. Upon
written request from Tenant, Landlord shall provide Tenant with written
information evidencing the matters described in the preceding sentence.
Landlord's determination of any excess assessed valuation shall be binding and
conclusive, absent manifest error. The amount of any such payment by Landlord
shall constitute Additional Rent due from Tenant to Landlord immediately upon
demand.

     10. PARKING. Tenant shall have the right to mark 2 two spaces, designated
by Landlord and in a manner acceptable to Landlord, for reserved parking by
Tenant and to park in common with other tenants of the Project in those areas
designated for non-reserved parking subject in each case to Landlord's rules and
regulations. Landlord may allocate parking spaces among Tenant and other tenants
in the Project if Landlord determines that such parking facilities are becoming
crowded. Landlord shall not be responsible and shall have no obligation for
enforcing Tenant's parking rights (including, without limitation, the reserved
parking rights) against any third parties, including other tenants of the
Project.

     11. UTILITIES, SERVICES.

         Landlord shall provide, subject to the terms of this Section 11, water,
electricity, heat, light, power, telephone, sewer, and other utilities
(including gas and fire sprinklers to the extent the Project is plumbed for such
services), refuse and trash collection and janitorial services (collectively,
"UTILITIES") Landlord shall pay, as Operating Expenses or subject to Tenant's
reimbursement obligation, for all Utilities used on the Premises, all
maintenance charges for Utilities, and any storm sewer charges or other similar
charges for Utilities imposed by any governmental entity or Utility provider,
and any taxes, penalties, surcharges or similar charges thereon. Landlord may
cause, at Tenant's expense, any Utilities to be separately metered or charged
directly to Tenant by the provider. Tenant shall pay directly to the Utility
provider, prior to delinquency, any separately metered Utilities and services
which may be furnished to Tenant or the Premises during the Term. Tenant shall
pay, as part of Operating Expenses, its share of all charges for jointly metered
Utilities based upon consumption, as reasonably determined by Landlord. No
interruption or failure of Utilities, from any cause whatsoever other than
Landlord's willful misconduct, shall result in eviction or constructive eviction
of Tenant, termination of this Lease or the abatement of Rent. Tenant agrees to
limit use of water and sewer with respect to Common Areas to normal restroom
use.

     12. ALTERATIONS AND TENANT'S PROPERTY. Any alterations, additions, or
improvements made to the Premises by or on behalf of Tenant, including
additional locks or bolts of any kind or nature upon any doors or windows in the
Premises, but excluding, after prior written notice to Landlord, interior
non-structural alterations costing less than $15,000 and

<PAGE>

installation, removal or realignment of furniture systems (other than removal of
furniture systems owned or paid for by Landlord) not involving any modifications
to the structure or connections (other then by ordinary plugs or jacks) to
building systems (as hereinafter defined) ("Alterations") shall be subject to
Landlord's prior written consent, which may be given or withheld in Landlord's
sole discretion if any such Alteration affects the structure or building
systems. If Landlord approves any Alterations, Landlord may impose such
conditions on Tenant in connection with the commencement, performance and
completion of such Alterations as Landlord may deem appropriate in Landlord's
reasonable discretion. Any request for approval shall be in writing, delivered
not less than 15 business days in advance of any proposed construction, and
accompanied by plans, specifications, bid proposals, work contracts and such
other information concerning the nature and cost of the alterations as may be
reasonably requested by Landlord, including the identities and mailing addresses
of all persons performing work or supplying materials. Landlord's right to
review plans and specifications and to monitor construction shall be solely for
its own benefit, and Landlord shall have no duty to ensure that such plans and
specifications or construction comply with applicable Legal Requirements. Tenant
shall cause, at its sole cost and expense, all Alterations to comply with
insurance requirements and with Legal Requirements and shall implement at its
sole cost and expense any alteration or modification required by Legal
Requirements as a result of any Alterations. Tenant shall pay to Landlord, as
Additional Rent, on demand an amount equal to 3% of all charges incurred by
Tenant or its contractors or agents in connection with any Alteration to cover
Landlord's overhead and expenses for plan review, coordination, scheduling and
supervision. Before Tenant begins any Alteration, Landlord may post on and about
the Premises notices of non-responsibility pursuant to applicable law. Tenant
shall reimburse Landlord for, and indemnify and hold Landlord harmless from, any
expense incurred by Landlord by reason of faulty work done by Tenant or its
contractors, delays caused by such work, or inadequate cleanup.

     Tenant shall furnish security or make other arrangements reasonably
satisfactory to Landlord to assure payment for the completion of all Alteration
work free and clear of liens, and shall provide certificates of insurance for
worker's compensation in statutory amounts and other coverage in amounts and
from an insurance company satisfactory to Landlord protecting Landlord against
liability for personal injury or property damage during construction. Upon
completion of any Alterations, Tenant shall deliver to Landlord: (i) sworn
statements setting forth the names of all contractors and subcontractors who did
the work and final lien waivers from all such contractors and subcontractors;
and (ii) as built plans for any such Alteration.

     Other than (i) the items, if any, listed on EXHIBIT F attached hereto and,
(ii) any items agreed by Landlord in writing to be included on EXHIBIT F in the
future, and (iii) any trade fixtures, machinery, equipment and other personal
property not paid for out of the TI Fund (as defined in the Work Letter) which
may be removed without material damage to the Premises, which damage shall be
repaired by Tenant during the Term (collectively, "TENANT'S PROPERTY"), all
property of any kind paid for with the TI Fund, all Alterations, real property
fixtures, built-in machinery and equipment, built-in casework and cabinets and
other similar additions and improvements built into the Premises so as to become
an integral part of the Premises such as fume hoods which penetrate the roof or
plenum area, built-in cold rooms, built-in warm rooms, walk-in cold rooms,
walk-in warm rooms, deionized water system, chillers, built-in plumbing,
electrical and mechanical equipment and systems, and any power generator and
transfer switch

<PAGE>

(collectively, "INSTALLATIONS") shall be and shall remain the property of
Landlord during the Term and following the expiration or earlier termination of
the Term, shall not be removed by Tenant at any time during the Term and shall
remain upon and be surrendered with the Premises as a part thereof following the
expiration or earlier termination of this Lease; PROVIDED, HOWEVER, that
Landlord shall, at the time its approval of such Installation is requested
notify Tenant if it has elected to cause Tenant to remove such Installation upon
the expiration or earlier termination of this Lease. If Landlord so elects,
Tenant shall remove such Installation upon the expiration or earlier termination
of this Lease and restore any damage caused by or occasioned as a result of such
removal, including, when removing any of Tenant's Property which was plumbed,
wired or otherwise connected to any of the building systems, capping off all
such connections behind the walls of the Premises and repairing any holes.
During any such restoration period, Tenant shall pay Rent to Landlord as
provided herein as if said space were otherwise occupied by Tenant.

     13. LANDLORD'S REPAIRS. Landlord, as an Operating Expense, shall maintain
all of the structural, exterior, parking and other Common Areas of the Project,
including HVAC, plumbing, fire sprinklers, elevators and all other building
systems serving the Premises and other portions of the Project ("BUILDING
SYSTEMS"), in good repair, reasonable wear and tear and uninsured losses and
damages caused by Tenant, its agents, servants, employees, invitees and
contractors excluded. Losses and damages caused by Tenant, its agents, servants,
employees, invitees and contractors shall be repaired by Landlord, to the extent
not covered by insurance, at Tenant's sole cost and expense. Landlord reserves
the right to stop Building System services when necessary (i) by reason of
accident or emergency, or (ii) for planned repairs, alterations or improvements,
which are, in the judgment of Landlord, desirable or necessary to be made, until
said repairs, alterations or improvements shall have been completed. Landlord
shall have no responsibility or liability for failure to supply Building System
services during any such period of interruption; PROVIDED, HOWEVER, that
Landlord shall give Tenant 24 hours advance notice of any planned stoppage of
Building System services for routine maintenance, repairs, alterations or
improvements. Tenant shall promptly give Landlord written notice of any repair
required by Landlord pursuant to this Section, after which Landlord shall have a
reasonable opportunity to effect such repair. Landlord shall not be liable for
any failure to make any repairs or to perform any maintenance unless such
failure shall persist for an unreasonable time after Tenant's written notice of
the need for such repairs or maintenance. Tenant waives it rights under any
state or local law to terminate this Lease or to make such repairs at Landlord's
expense and agrees that the parties' respective rights with respect to such
matters shall be solely as set forth herein. Repairs required as the result of
fire, earthquake, flood, vandalism, war, or similar cause of damage or
destruction shall be controlled by Section 18.

     14. TENANT'S REPAIRS. Subject to Section 13 hereof, Tenant, at its
expense, shall repair, replace and maintain in good condition all portions of
the Premises, including, without limitation, entries, doors, ceilings, interior
windows, interior walls, and the interior side of demising walls. Such repair
and replacements may include capital expenditures and repairs whose benefit may
extend beyond the Term. Should Tenant fail to make any such repair or
replacement or fail to maintain the Premises, Landlord shall give Tenant notice
of such failure. If Tenant fails to commence cure of such default within 10 days
of Landlord's notice, and thereafter diligently prosecute such cure to
completion, Landlord may perform such work and shall be reimbursed by Tenant
within 10 days after demand therefor; provided, however, that if such default by
Tenant creates or could create an emergency, Landlord may immediately

<PAGE>

commence cure of such default and shall thereafter be entitled to recover the
costs of such cure from Tenant. Subject to Sections 1 7 and 18, Tenant shall
bear the full uninsured cost of any repair or replacement to any part of the
Project that results from damage caused by Tenant, its agents, contractors, or
invitees and any repair that benefits only the Premises.

     15. MECHANIC'S LIENS. Tenant shall discharge, by bond or otherwise, any
mechanic's lien filed against the Premises or against the Project for work
claimed to have been done for, or materials claimed to have been furnished to,
Tenant within 15 days after the filing thereof, at Tenant's sole cost and shall
otherwise keep the Premises and the Project free from any liens arising out of
work performed, materials furnished or obligations incurred by Tenant. Should
Tenant fail to discharge any lien described herein, Landlord shall have the
right, but not the obligation, to pay such claim or post a bond or otherwise
provide security to eliminate the lien as a claim against title to the Project
and the cost thereof shall be immediately due from Tenant as Additional Rent. If
Tenant shall lease or finance the acquisition of office equipment, furnishings,
or other personal property of a removable nature utilized by Tenant in the
operation of Tenant's business, Tenant warrants that any Uniform Commercial Code
Financing Statement executed by Tenant will upon its face or by exhibit thereto
indicate that such Financing Statement is applicable only to removable personal
property of Tenant located within the Premises. In no event shall the address of
the Project be furnished on the statement without qualifying language as to
applicability of the lien only to removable personal property, located in an
identified suite held by Tenant.

     16. INDEMNIFICATION. Tenant hereby indemnifies and agrees to defend, save
and hold Landlord harmless from and against any and all Claims for injury or
death to persons or damage to property occurring within or about the Premises,
arising directly or indirectly out of Tenant's use or occupancy of the Premises
or a breach or default by Tenant in the performance of any of its obligations
hereunder, unless caused solely by the willful misconduct or gross negligence of
Landlord or its agents or contractors (to the extent such agents or contractors
are acting within the scope of the their authority). Landlord shall not be
liable to Tenant for, and Tenant assumes all risk of damage to, personal
property (including, without limitation, loss of records kept within the
Premises). Tenant further waives any and all Claims for injury to Tenant's
business or loss of income relating to any such damage or destruction of
personal property (including, without limitation, any loss of records). Landlord
shall not be liable for any damages arising from any act, omission or neglect of
any tenant in the Project or of any other third party.

     17. INSURANCE. Landlord shall maintain all insurance against any peril
generally included within the classification "Fire and Extended Coverage,"
sprinkler damage (if applicable), vandalism and malicious mischief covering the
full replacement cost of the Project or such lesser coverage amount as Landlord
may elect PROVIDED such coverage amount is not less than 90% of such full
replacement cost. Landlord shall further carry commercial general liability
insurance with a single loss limit of not less than $2,000,000 for death or
bodily injury, or property damage with respect to the Project. Landlord may, but
is not obligated to, maintain such other insurance and additional coverages as
it may deem necessary, including, but not limited to, flood, environmental
hazard and earthquake, loss or failure of building equipment, errors and
omissions, rental loss during the period of repair or rebuilding, workmen's
compensation insurance and fidelity-bonds for employees employed to perform
services and insurance for any improvements installed by Tenant or which are in
addition to the standard

<PAGE>

improvements customarily furnished by Landlord without regard to whether or not
such are made a part of the Project. All such insurance shall be included as
part of the Operating Expenses. The Project may be included in a blanket policy
(in which case the cost of such insurance allocable to the Project will be
determined by Landlord based upon the insurer's cost calculations). Tenant shall
also reimburse Landlord for any increased premiums or additional insurance which
Landlord reasonably deems necessary as a result of Tenant's use of the Premises.

     Tenant, at its sole cost and expense, shall maintain during the Term: all
risk property insurance covering the full replacement cost of all property and
improvements installed or placed in the Premises by Tenant at Tenant's expense
(excluding items paid for out of the TI Fund); worker's compensation insurance
with no less than the minimum limits required by law; employer's liability
insurance with such limits as required by law; and commercial general liability
insurance, with a minimum limit of not less than $2,000,000 per occurrence for
death or bodily injury and not less than $1,000,000 for property damage with
respect to the Premises. The commercial general liability insurance policies
shall name Landlord, its officers, directors, employees, managers, agents,
invitees and contractors (collectively, "Related Parties"), as additional
insureds; insure on an occurrence and not a claims-made basis; be issued by
insurance companies which have a rating of not less than policyholder rating of
A and financial category rating of at least Class XII in "Best's Insurance
Guide"; shall not be cancelable unless 30 days prior written notice shall have
been given to Landlord from the insurer; contain a hostile fire endorsement and
a contractual liability endorsement; and provide primary coverage to Landlord
(any policy issued to Landlord providing duplicate or similar coverage shall be
deemed excess over Tenant's policies). Such policies or certificates thereof
shall be delivered to Landlord by Tenant upon commencement of the Term and upon
each renewal of said insurance. Tenant's policy may be a "blanket policy" which
specifically provides that the amount of insurance shall not be prejudiced by
other losses covered by the policy. Tenant shall, at least 20 days prior to the
expiration of such policies, furnish Landlord with renewals or binders. Tenant
agrees that if Tenant does not take out and maintain such insurance, Landlord
may (but shall not be required to) procure said insurance on Tenant's behalf and
at its cost to be paid as Additional Rent.

     In each instance where insurance is to name Landlord as additional insured,
Tenant shall upon written request of Landlord also designate and furnish
certificates so evidencing Landlord as additional insured to: (i) any lender of
Landlord holding a security interest in the Project or any portion thereof, (ii)
the landlord under any lease wherein Landlord is tenant of the real property on
which the Project is located, if the interest of Landlord is or shall become
that of a tenant under a ground lease rather than that of a fee owner, and/or
(iii) any management company retained by Landlord to manage the Project.

     The property insurance obtained by Landlord and Tenant shall include a
waiver of subrogation by the insurers and all rights based upon an assignment
from its insured, against Landlord or Tenant, and their respective Related
Parties, in connection with any loss or damage thereby insured against. Neither
party nor its respective Related Parties shall be liable to the other for loss
or damage caused by any risk insured against under property insurance required
to be maintained hereunder, and each party waives any claims against the other
party, and its respective Related Parties for such loss or damage. The failure
of a party to insure its property shall not void this waiver. Landlord and its
respective Related Parties shall not be liable for, and

<PAGE>

Tenant hereby waives all claims against such parties for, business interruption
and losses occasioned thereby sustained by Tenant or any person claiming through
Tenant resulting from any accident or occurrence in or upon the Premises or the
Project from any cause whatsoever. If the foregoing waivers shall contravene any
law with respect to exculpatory agreements, the liability of Landlord or Tenant
shall be deemed not released but shall be secondary to the other's insurer.

     Landlord may require insurance policy limits to be raised to conform with
requirements of Landlord's lender and to bring coverage limits to levels
standard for the Permitted Use in this type of building in Worcester,
Massachusetts.

     18. RESTORATION. If at any time during the Term the Project or the Premises
are damaged by a fire or other insured casualty, Landlord shall notify Tenant
("Landlord's Notice") within 30 days after discovery of such damage as to the
amount of time Landlord reasonably estimates it will take to restore the Project
or the Premises, as applicable. If the restoration time is estimated to exceed
12 months, Landlord may, in such notice, elect to terminate this Lease as of the
date that is 45 days after the date of discovery of such damage or destruction.
If Landlord's Notice states that the restoration time is estimated to exceed 12
months, Tenant shall have the right to elect to terminate this Lease as of the
date that is 10 days after Landlord's Notice; provided, however, that Tenant's
right to terminate shall expire if not exercised within 5 days after Landlord's
Notice. Unless Landlord or Tenant elects to terminate this Lease, Landlord
shall, subject to receipt of sufficient insurance proceeds (with any deductible
to be treated as a current Operating Expense), promptly restore the Premises
(excluding the improvements installed by Tenant or by Landlord and paid for by
Tenant but including items paid for out of the Tl Fund), subject to delays
arising from the collection of insurance proceeds, from Force Majeure events or
as needed to obtain any license, clearance or other authorization of any kind
required to enter into and restore the Premises issued by any governmental or
quasi-governmental agency having jurisdiction over the use, storage, release or
removal of Hazardous Materials in, on or about the Premises (collectively
referred to herein as "Hazardous Materials Clearances"); provided, however, that
if repair or restoration of the Premises is not Substantially Complete as of the
end of 12 months from the date of damage or destruction, Landlord may, in its
sole and absolute discretion, elect not to proceed with such repair and
restoration, in which event Landlord shall be relieved of its obligation to make
such repairs or restoration and this Lease shall terminate as of the date that
is 5 days after written notice to Tenant of Landlord's election to terminate
this Lease. If repair or restoration of the Premises is not Substantially
Complete as of the end of 12 months from the date of damage or destruction,
Tenant shall have the right to terminate this Lease upon the date that is 5 days
after written notice to Landlord of Tenant's election to terminate this Lease;
provided, however, that Tenant's right to terminate shall expire if not
exercised within 10 days after the end of 12 months from the date of damage or
destruction. Notwithstanding the foregoing, if insurance proceeds are not
available for restoration of the Premises or the Building solely by reason of
Landlord's failure to maintain the insurance required to be maintained by
Landlord under Section 17 hereof, Landlord shall be responsible for the costs of
restoration to the extent of the insurance proceeds that would have been
available had Landlord performed its obligations pursuant to Section 17 hereof.

     Tenant, at its expense, shall promptly perform, subject to delays arising
from the collection of insurance proceeds, from Force Majeure events or to
obtain Hazardous Material

<PAGE>

Clearances, all repairs or restoration not required to be done by Landlord and
shall promptly re-enter the Premises and commence doing business in accordance
with this Lease. Notwithstanding the foregoing, (i) Landlord may terminate this
Lease if the Premises are damaged during the last 2 years of the Term and
Landlord reasonably estimates that it will take more than one month to repair
such damage, or if insurance proceeds are not available for such restoration,
and (ii) Tenant may terminate this Lease if the Premises are damaged during the
last 12 months of the Term and Landlord reasonably estimates that it will take
more than 90 days to repair such damage; provided, however, Tenant's right to
terminate shall expire if not exercised within 5 days after Landlord's notice to
Tenant stating how long repairs are estimated to take. Rent shall be abated from
the date all required Hazardous Material Clearances are obtained until the
Premises are repaired and restored, in the proportion which the area of the
Premises, if any, which is not usable by Tenant bears to the total area of the
Premises, unless Landlord provides Tenant with other space during the period of
repair that is suitable for the temporary conduct of Tenant's business. Such
abatement shall be the sole remedy of Tenant, and except as provided herein,
Tenant waives any right to terminate the Lease by reason of damage or casualty
loss.

     The provisions of this Lease, including this Section 18, constitute an
express agreement between Landlord and Tenant with respect to any and all damage
to, or destruction of, all or any part of the Premises, or any other portion of
the Project, and any statute or regulation which is now or may hereafter be in
effect, shall have no application to this Lease or any damage or destruction to
all or any part of the Premises or any other portion of the Project, the parties
hereto expressly agreeing this Section 1 8 sets forth their entire understanding
and agreement with respect to such matters.

     19. CONDEMNATION. If any part of the Premises or the Project is taken for
any public or quasi-public use under governmental law, ordinance, or regulation,
or by right of eminent domain, or by private purchase in lieu thereof (a
"TAKING" or "TAKEN"), and the Taking would in Landlord's judgment either prevent
or materially interfere with Tenant's use of the Premises or materially
interfere with or impair Landlord's ownership or operation of the Project, then
upon written notice by Landlord this Lease shall terminate and Rent shall be
apportioned as of said date. If all or part of the Premises is taken and Tenant
is unable to use the Premises for the Permitted Use, Tenant shall have the right
to terminate this Lease upon the date that is 5 days after written notice to
Landlord of Tenant's election to terminate this Lease and Rent shall be
apportioned as of said date; provided, however, that Tenant's right to terminate
shall expire if not exercised within 10 days after the date of the order of
condemnation. If part of the Premises shall be Taken, and this Lease is not
terminated as provided above, Landlord shall promptly restore the Premises and
the Project as nearly as is commercially reasonable under the circumstances to
their condition prior to such partial taking and the Rent payable hereunder
during the unexpired Term shall be reduced to such extent as may be fair and
reasonable under the circumstances. Upon any such Taking, Landlord shall be
entitled to receive the entire price or award from any such Taking without any
payment to Tenant, and Tenant hereby assigns to Landlord Tenant's interest, if
any, in such award. Tenant shall have the right, to the extent that same shall
not diminish Landlord's award, to make a separate claim against the condemning
authority (but not Landlord) for such compensation as may be separately awarded
or recoverable by Tenant for moving expenses and damage to Tenant's Trade
Fixtures, if a separate award for such items is made to Tenant. Tenant hereby
waives any and all rights it might otherwise have

<PAGE>

pursuant to any provision of state law to terminate this Lease upon a partial
Taking of the Premises or the Project.

     20. EVENTS OF DEFAULT. Each of the following events shall be a default
("Default") by Tenant under this Lease:

     (a) PAYMENT DEFAULTS. Tenant shall fail to pay any installment of Rent or
any other payment hereunder when due; PROVIDED, HOWEVER, that Landlord, not more
than once in any 12 month period, will give Tenant notice of such default in the
payment of Rent and Tenant shall have 3 days in which to make such payment after
which period Tenant shall be in Default hereunder. Tenant agrees that such
notice shall be in lieu of and not in addition to any notice required by law.

     (b) INSURANCE. Any insurance required to be maintained by Tenant pursuant
to this Lease shall be canceled or terminated or shall expire or shall be
reduced or materially adversely changed, or Landlord shall receive a notice of
nonrenewal of any such insurance and Tenant shall fail to obtain replacement
insurance at least 20 days before the expiration of the current coverage.

     (c) ABANDONMENT. Tenant shall abandon the Premises and otherwise be in
default under this Lease.

     (d) IMPROPER TRANSFER. Tenant shall assign, sublease or otherwise transfer
or attempt to transfer all or any portion of Tenant's interest in this Lease or
the Premises except as expressly permitted herein, or Tenant's interest in this
Lease shall be attached, executed upon, or otherwise judicially seized and such
action is not released within 90 days of the action.

     (e) LIENS. Tenant shall fail to discharge or otherwise obtain the release
of any lien placed upon the Premises in violation of this Lease within 10 days
after Tenant has received notice that any such lien is filed against the
Premises.

     (f) INSOLVENCY EVENTS. Tenant or any guarantor or surety of Tenant's
obligations hereunder shall: (A) make a general assignment for the benefit of
creditors; (B) commence any case, proceeding or other action seeking to have an
order for relief entered on its behalf as a debtor or to adjudicate it a
bankrupt or insolvent, or seeking reorganization, arrangement, adjustment,
liquidation, dissolution or composition of it or its debts or seeking
appointment of a receiver, trustee, custodian or other similar official for it
or for all or of any substantial part of its property (collectively a
"PROCEEDING FOR RELIEF"); (C) become the subject of any Proceeding for Relief
which is not dismissed within 90 days of its filing or entry; or (D) die or
suffer a legal disability (if Tenant, guarantor, or surety is an individual) or
be dissolved or otherwise fail to maintain its legal existence (if Tenant,
guarantor or surety is a corporation, partnership or other entity).

     (g) ESTOPPEL CERTIFICATE OR SUBORDINATION AGREEMENT. Tenant fails to
execute any document required from Tenant under Sections 23 or 27 within 10 days
after a second notice requesting such document.

<PAGE>

     (h) OTHER DEFAULTS. Tenant shall fail to comply with any provision of this
Lease other than those specifically referred to in this Section 20*, and except
as otherwise expressly provided herein, such failure shall continue for a period
of 10 days after written notice thereof from Landlord to Tenant.

Any notice given under Section 20 (h) hereof, shall: (i) specify the alleged
default, (ii) demand that Tenant cure such default, (iii) be in lieu of, and not
in addition to, or shall be deemed to be any notice required under any provision
of applicable law, and (iv) not be deemed a forfeiture or a termination of this
Lease unless Landlord elects otherwise in such notice; PROVIDED that if the
nature of Tenant's default pursuant to Section 20(h) is such that it cannot be
cured by the payment of money and reasonably requires more than 10 days to cure,
then Tenant shall not be deemed to be in default if Tenant commences such cure
within said 10 day period and thereafter diligently prosecutes the same to
completion; provided, however, that such cure shall be completed no later than
90 days from the date of Landlord's notice.

     21. LANDLORD'S REMEDIES.

     (a) PAYMENT BY LANDLORD; INTEREST. Upon a Default by Tenant hereunder,
Landlord may, without waiving or releasing any obligation of Tenant hereunder,
make such payment or perform such act. All sums so paid or incurred by Landlord,
together with interest thereon, from the date such sums were paid or incurred,
at the annual rate equal to 12% per annum or the highest rate permitted by law
(the "Default Rate"), whichever is less, shall be payable to Landlord on demand
as Additional Rent. Nothing herein shall be construed to create or impose a duty
on Landlord to mitigate any damages resulting from Tenant's Default hereunder.

     (b) LATE PAYMENT RENT. Late payment by Tenant to Landlord of Rent and other
sums due will cause Landlord to incur costs not contemplated by this Lease, the
exact amount of which will be extremely difficult and impracticable to
ascertain. Such costs include, but are not limited to, processing and accounting
charges and late charges which may be imposed on Landlord under any Mortgage
covering the Premises. Therefore, if any installment of Rent due from Tenant is
not received by Landlord within 5 days after the date such payment is due,
Tenant shall pay to Landlord an additional sum of 6% of the overdue Rent as a
late charge. The parties agree that this late charge represents a fair and
reasonable estimate of the costs Landlord will incur by reason of late payment
by Tenant. In addition to the late charge, Rent not paid when due shall bear
interest at the Default Rate from the 5th day after the date due until paid.

     (c) REMEDIES. Upon the occurrence of a Default, Landlord, at its option,
without further notice or demand to Tenant, shall have in addition to all other
rights and remedies provided in this Lease, at law or in equity, the option to
pursue any one or more of the following remedies, each and all of which shall be
cumulative and nonexclusive, without any notice or demand whatsoever.

         (i) Terminate this Lease, or at Landlord's option, Tenant's right to
possession only, in which event Tenant shall immediately surrender the Premises
to Landlord, and if Tenant fails to do so, Landlord may, without prejudice to
any other remedy which it may have for possession or arrearages in rent, enter
upon and take possession of the Premises and expel or

<PAGE>

remove Tenant and any other person who may be occupying the Premises or any part
thereof, without being liable for prosecution or any claim or damages therefor;

         (ii) Upon any termination of this Lease, whether pursuant to the
foregoing Section 21(c)(i) or otherwise, Landlord may recover from Tenant the
following:

              (A) The worth at the time of award of any unpaid rent which has
been earned at the time of such termination; plus

              (B) The worth at the time of award of the amount by which the
unpaid rent which would have been earned after termination until the time of
award exceeds the amount of such rental loss that Tenant proves could have been
reasonably avoided; plus

              (C) The worth at the time of award of the amount by which the
unpaid rent for the balance of the Term after the time of award exceeds the
amount of such rental loss that Tenant proves could have been reasonably
avoided; plus

              (D) Any other amount necessary to compensate Landlord for all the
detriment proximately caused by Tenant's failure to perform its obligations
under this Lease or which in the ordinary course of things would be likely to
result therefrom, specifically including but not limited to, brokerage
commissions and advertising expenses incurred, expenses of remodeling the
Premises or any portion thereof for a new tenant, whether for the same or a
different use; and

              (E) At Landlord's election, such other amounts in addition to or
in lieu of the foregoing as may be permitted from time to time by applicable
law.

     The term "RENT" as used in this Section 21 shall be deemed to be and to
mean all sums of every nature required to be paid by Tenant pursuant to the
terms of this Lease, whether to Landlord or to others. As used in Sections 21
(c)(ii) (A) and (B), above, the "WORTH AT THE TIME OF AWARD" shall be computed
by allowing interest at the Default Rate. As used in Section 21 (c)(ii)(C)
above, the "WORTH AT THE TIME OF AWARD" shall be computed by discounting such
amount at the discount rate of the Federal Reserve Bank of San Francisco at the
time of award plus 1%.

         (iii) Landlord may continue this Lease in effect after Tenant's Default
and recover rent as it becomes due. Accordingly, if Landlord does not elect to
terminate this Lease following a Default by Tenant, Landlord may, from time to
time, without terminating this Lease, enforce all of its rights and remedies
hereunder, including the right to recover all Rent as it becomes due.

         (iv) Whether or not Landlord elects to terminate this Lease following a
Default by Tenant, Landlord shall have the right to terminate any and all
subleases, licenses, concessions or other consensual arrangements for possession
entered into by Tenant and affecting the Premises or may, in Landlord's sole
discretion, succeed to Tenant's interest in such subleases, licenses,
concessions or arrangements. Upon Landlord's election to succeed to Tenant's
interest in any such subleases, licenses, concessions or arrangements, Tenant
shall, as

<PAGE>

of the date of notice by Landlord of such election, have no further right to or
interest in the rent or other consideration receivable thereunder.

         (v) Independent of the exercise of any other remedy of Landlord
hereunder or under applicable law, Landlord may conduct an environmental test of
the Premises as generally described in Section 30(d) hereof. If contamination
has occurred for which Tenant is liable under Section 30 hereof, Tenant shall
pay all costs to conduct such tests. If no such contamination is found, Landlord
shall pay the costs of such tests.

     (d) EFFECT OF EXERCISE. Exercise by Landlord of any remedies hereunder or
otherwise available shall not be deemed to be an acceptance of surrender of the
Premises and/or a termination of this Lease by Landlord, it being understood
that such surrender and/or termination can be effected only by the express
written agreement of Landlord and Tenant. Any law, usage, or custom to the
contrary notwithstanding, Landlord shall have the right at all times to enforce
the provisions of this Lease in strict accordance with the terms hereof; and the
failure of Landlord at any time to enforce its rights under this Lease strictly
in accordance with same shall not be construed as having created a custom in any
way or manner contrary to the specific terms, provisions, and covenants of this
Lease or as having modified the same and shall not be deemed a waiver of
Landlord's right to enforce one or more of its rights in connection with any
subsequent default. A receipt by Landlord of Rent or other payment with
knowledge of the breach of any covenant hereof shall not be deemed a waiver of
such breach, and no waiver by Landlord of any provision of this Lease shall be
deemed to have been made unless expressed in writing and signed by Landlord. To
the greatest extent permitted by law, Tenant waives the service of notice of
Landlord's intention to re-enter, re-take or otherwise obtain possession of the
Premises as provided in any statute, or to institute legal proceedings to that
end, and 'also waives all right of redemption in case Tenant shall be
dispossessed by a judgment or by warrant of any court or judge. Any reletting of
the Premises or any portion thereof shall be on such terms and conditions as
Landlord in its sole discretion may determine. Landlord shall not be liable, nor
shall Tenant's obligations hereunder be diminished because of, Landlord's
failure to relet the Premises or collect rent due in respect of such reletting
or otherwise to mitigate any damages arising by reason of Tenant' Default.

     22. ASSIGNMENT AND SUBLETTING.

     (a) GENERAL PROHIBITION. Except for subleasing a portion of the Premises to
Antigen Express, Inc., and E-Z-Em, Inc., without Landlord's prior written
consent subject to and on the conditions described in this Section 22, Tenant
shall not, directly or indirectly, voluntarily or by operation of law, assign
this Lease or sublease the Premises or any part thereof or mortgage, pledge, or
hypothecate its leasehold interest or grant any concession or license within the
Premises and any attempt to do any of the foregoing shall be void and of no
effect. If Tenant is a corporation, partnership or limited liability company,
the shares or other ownership interests of Tenant which are not actively traded
'upon a stock exchange or in the over-the-counter market, a transfer or series
of transfers whereby 35% or more of the issued and outstanding shares or other
ownership interests of such corporation are, or voting control, is, transferred
("Stock Transfer") (but excepting transfers upon deaths of individual owners or
for estate planning purposes) from a person or persons or entity or entities
which were owners thereof at time of execution of this Lease to persons or
entities who were not owners of shares of the corporation, partnership or

<PAGE>

limited liability company at time of execution of this Lease, shall be deemed an
assignment of this Lease requiring the consent of Landlord. Landlord may in
connection with a Stock Transfer request and consider such information as
Landlord deems necessary or appropriate to its consideration whether to grant
its consent to such Stock Transfer. Landlord shall grant or refuse such consent
in its reasonable discretion; provided, however, that Tenant acknowledges that
it shall be reasonable for Landlord to refuse consent to any assignment which
(i) may have the potential to negatively impact the financial condition of
Tenant or the likelihood or ability of Tenant to perform its obligations under
this Lease, (ii) is not for a rational business purpose, or (iii) is principally
for the purpose of transferring the Lease.

     (b) Permitted Transfers. If Tenant desires to assign, sublease, hypothecate
or otherwise transfer this Lease or sublet the Premises, then at least 15
business days, but not more than 45 business days, before the date Tenant
desires the assignment or sublease to be effective (the "ASSIGNMENT DATE"),
Tenant shall give Landlord a notice (the "ASSIGNMENT NOTICE") containing such
information about the proposed assignee or sublessee, including the proposed use
of the Premises and any Hazardous Materials proposed to be used or stored in the
Premises, the Assignment Date, any relationship between Tenant and the proposed
assignee or sublessee, and all material terms and conditions of the proposed
assignment or sublease, including a copy of any proposed sublease in its final
form, and such other information as Landlord may deem reasonably necessary or
appropriate to its consideration whether to grant its consent. Landlord may, by
giving written notice to Tenant within 1 5 business days after receipt of the
Assignment Notice: (i) grant or refuse such consent, in its sole discretion with
respect to a proposed assignment, hypothecation or other transfer or subletting
of more than (together with all other then effective subleases) 50% of the
Premises, or grant or refuse such consent, in its reasonable discretion with
respect to a proposed subletting of up to (together with all other then
effective subleases) 50% of the Premises (provided that Landlord shall further
have the right to review and approve or disapprove the proposed form of sublease
prior to the effective date of any such subletting), or with respect to a Stock
Transfer, or (ii) terminate this Lease with respect to they space described in
the Assignment Notice, as of the Assignment Date (an "Assignment Termination").
If Landlord elects an Assignment Termination, Tenant shall have the right to
withdraw such Assignment Notice by written notice to Landlord of such election
within 10 days after Landlord's notice electing to exercise the Assignment
Termination. If Tenant withdraws such Assignment Notice, this Lease shall
continue in full force and effect. If Tenant does not withdraw such Assignment
Notice, this Lease, and the term and estate herein granted, shall terminate as
of the Assignment Date with respect to the space described in such Assignment
Notice. No failure of Landlord to exercise any such option to terminate this
Lease shall be deemed to be Landlord's consent to the proposed assignment,
sublease or other transfer. Tenant shall reimburse Landlord for all of
Landlord's reasonable out-of-pocket expenses in connection with its
consideration of any Assignment Notice.

     (c) Additional Conditions. As a condition to any such assignment or
subletting, whether or not Landlord's consent is required, Landlord may require:

         (i) that any assignee or subtenant agree, in writing at the time of
such assignment or subletting, that, following the occurrence of a Default
hereunder, if Landlord gives such party written notice that Tenant is in default
under this Lease, such party shall thereafter make all payments otherwise due
Tenant directly to Landlord, which payments will be received

<PAGE>

by Landlord without any liability except to credit such payment against those
due under the Lease, and any such third party shall agree to attorn to Landlord
or its successors and assigns should this Lease be terminated for any reason;
PROVIDED, HOWEVER, in no event shall Landlord or its successors or assigns be
obligated to accept such attornment; and

     A list of Hazardous Materials, certified by the proposed assignee or
sublessee to be true and correct, which the proposed assignee or sublessee
intends to use or store in the Premises together with copies of all documents
relating to the handling, storage, disposal and emission of Hazardous Materials
by the proposed assignee or subtenant in the Premises or on the Project, prior
to the proposed assignment or subletting, including, without limitation:
permits; approvals; reports and correspondence; storage and management plans;
plans relating to the installation of any storage tanks to be installed in or
under the Project (provided, said installation of tanks shall only be permitted
after Landlord has given its written consent to do so, which consent may be
withheld in Landlord's sole and absolute discretion); and all closure plans or
any other documents required by any and all federal, state and local
governmental agencies and authorities for any storage tanks installed in, on or
under the Project for the closure of any such tanks. Neither Tenant nor any such
proposed assignee or subtenant is required, however, to provide Landlord with
any portion(s) of the such documents containing information of a proprietary
nature which, in and of themselves, do not contain a reference to any Hazardous
Materials or hazardous activities.

     (d) NO RELEASE OF TENANT, SHARING OF EXCESS RENTS. Notwithstanding any
assignment or subletting, Tenant and any guarantor or surety of Tenant's
obligations under this Lease shall at all times remain fully and primarily
responsible and liable for the payment of Rent and for compliance with all of
Tenant's other obligations under this Lease. If the Rent due and payable by a
sublessee or assignee (or a combination of the rental payable under such
sublease or assignment plus any bonus or other consideration therefor or
incident thereto) exceeds the rental payable under this Lease, (excluding
however, any Rent payable under this Section), then Tenant shall be bound and
obligated to pay Landlord as Additional Rent hereunder 50% of such excess rental
and other excess consideration within 10 days following receipt thereof by
Tenant. If Tenant shall sublet the Premises or any part thereof, Tenant hereby
immediately and irrevocably assigns to Landlord, as security for Tenant's
obligations under this Lease, all rent from any such subletting and Landlord as
assignee and as attorney-in-fact for Tenant, or a receiver for Tenant appointed
on Landlord's application, may collect such rent and apply it toward Tenant's
obligations under this Lease; except that, until the occurrence of a Default,
Tenant shall have the right to collect such rent.

     (e) NO WAIVER. The consent by Landlord to an assignment or subletting shall
not relieve Tenant or any assignees of this Lease or any sublessees of the
Premises from obtaining the consent of Landlord to any further assignment or
subletting nor shall it release Tenant or any assignee or sublessee of Tenant
from full and primary liability under the Lease. The acceptance of Rent
hereunder, or the acceptance of performance of any other term, covenant, or
condition thereof, from any other person or entity shall not be deemed to be a
waiver of any of the provisions of this Lease or a consent to any subletting,
assignment or other transfer of the Premises.

<PAGE>

     (f) TERMINATION OF LEASE. Notwithstanding any other provision of this
Section 22, if (i) the proposed assignee or sublessee of Tenant has been
required by any prior landlord, lender or governmental authority to take
remedial action in connection with Hazardous Materials contaminating a property,
where the contamination resulted from such party's action or use of the property
in question, or (ii) the proposed assignee or sublessee is subject to an
enforcement order issued by any governmental authority in connection with the
use, disposal or storage of a Hazardous Materials, Landlord shall have the
absolute right to refuse to consent to any assignment or subletting to any such
party.

     23. ESTOPPEL CERTIFICATE. Tenant shall within 10 business days after
written notice from Landlord, execute, acknowledge and deliver a statement in
writing substantially in the form attached to this Lease as EXHIBIT G with the
blanks filled in, and on any other form reasonably requested by a proposed
lender or purchaser, (i) certifying that this Lease is unmodified and in full
force and effect (or, if modified, stating the nature of such modification and
certifying that this Lease as so modified is in full force and effect) and the
dates to which the rental and other charges are paid in advance, if any, (ii)
acknowledging that there are not any uncured defaults on the part of Landlord
hereunder, or specifying such defaults if any are claimed, and (iii) setting
forth such further information with respect to the status of this Lease or the
Premises as may be reasonably requested thereon. Any such statement may be
relied upon by any prospective purchaser or encumbrancer of all or any portion
of the real property of which the Premises are a part. Tenant's failure to
deliver such statement within such time shall, at the option of Landlord,
constitute a Default under this Lease, and, in any event, shall be conclusive
upon Tenant that the Lease is in full force and effect and without modification
except as may be represented by Landlord in any certificate prepared by Landlord
and delivered to Tenant for execution.

     24. QUIET ENJOYMENT. So long as Tenant shall perform all of the covenants
and agreements herein required to be performed by Tenant, Tenant shall, subject
to the terms of this Lease, at all times during the Term, have peaceful and
quiet enjoyment of the Premises against any person claiming by, through or under
Landlord.

     25. PRORATIONS. All prorations required or permitted to be made hereunder
shall be made on the basis of a 360 day year and 30 day months.

     26. RULES AND REGULATIONS. Tenant shall, at all times during the Term and
any extension thereof, comply with all reasonable rules and regulations at any
time or from time to time established by Landlord covering use of the Premises
and the Project. The current rules and regulations are attached hereto as
Exhibit E. If there is any conflict between said rules and regulations and other
provisions of this Lease, the terms and provisions of this Lease shall control.
Landlord shall not have any liability or obligation for the breach of any rules
or regulations by other tenants in the Project.

     27. SUBORDINATION. This Lease and Tenant's interest and rights hereunder
are and shall be subject and subordinate at all times to the lien of any
Mortgage, now existing or hereafter created on or against the Project or the
Premises, and all amendments, restatements, renewals, modifications,
consolidations, refinancing, assignments and extensions thereof, without the
necessity of any further instrument or act on the part of Tenant; provided,
however that so long as there is no Default hereunder, Tenant's right to
possession of the Premises shall

<PAGE>

not be disturbed by the Holder of any such Mortgage. Tenant agrees, at the
election of the Holder of any such Mortgage, to attorn to any such Holder.
Tenant agrees upon demand to execute, acknowledge and deliver a Subordination,
Non-disturbance and Attornment Agreement in the form attached hereto as Exhibit
H, or such other instruments, confirming such subordination and such instruments
of attornment as shall be requested by any such Holder, provided any such
instruments contain appropriate non-disturbance provisions assuring Tenant's
quiet enjoyment of the Premises as set forth in Section 24 hereof and a copy of
the same executed by any such Holder is delivered to Tenant. Notwithstanding the
foregoing, any such Holder may at any time subordinate its Mortgage to this
Lease, without Tenant's consent, by notice in writing to Tenant, and thereupon
this Lease shall be deemed prior to such Mortgage without regard to their
respective dates of execution, delivery or recording and in that event such
Holder shall have the same rights with respect to this Lease as though this
Lease had been executed prior to the execution, delivery and recording of such
Mortgage and had been assigned to such Holder. The term "Mortgage" whenever used
in this Lease shall be deemed to include deeds of trust, security assignments
and any other encumbrances, and any reference to the "Holder" of a mortgage
shall be deemed to include the beneficiary under a deed of trust.

     28. SURRENDER. Upon expiration of the Term or earlier termination of
Tenant's right of possession, Tenant shall surrender the Premises to Landlord in
the same condition as received, subject to any Alterations permitted by Landlord
to remain in the Premises, free of Hazardous Materials brought upon, kept or
used in or about the Premises or the Project by any person other than Landlord,
its agents, employees, contractors or invitees and released of all Hazardous
Materials Clearances, broom clean, ordinary wear and tear and casualty loss and
condemnation excepted. Tenant shall immediately return to Landlord all keys
and/or access cards to parking, the Project, restrooms or all or any portion of
the Premises furnished to, or otherwise procured by Tenant. If any such access
card or key is lost, Tenant shall pay to Landlord, at Landlord's election,
either the cost of replacing such lost access card or key or the cost of
reprogramming the access security system in which such access card was used or
changing the lock or locks opened by such lost key. Any Tenant's Property,
Alterations and property not so removed by Tenant as permitted or required
herein shall be deemed abandoned and may be stored, removed, and disposed of by
Landlord at Tenant's expense, and Tenant waives all claims against Landlord for
any damages resulting from Landlord's retention and/or disposition of such
property. All obligations of Tenant hereunder not fully performed as of the
termination of the Term, including the obligations of Tenant under Section 30
hereof, shall survive the expiration or earlier termination of the Term,
including without limitation, indemnity obligations, payment obligations with
respect to Rent and obligations concerning the condition and repair of the
Premises for a period of three (3) years after expiration or earlier
termination of the Term.

     29. WAIVER OF JURY TRIAL. TENANT AND LANDLORD WAIVE ANY RIGHT TO TRIAL BY
JURY OR TO HAVE A JURY PARTICIPATE IN RESOLVING ANY DISPUTE, WHETHER SOUNDING IN
CONTRACT, TORT, OR OTHERWISE, BETWEEN LANDLORD AND TENANT ARISING OUT OF THIS
LEASE OR ANY OTHER INSTRUMENT, DOCUMENT, OR AGREEMENT EXECUTED OR DELIVERED IN
CONNECTION HEREWITH OR THE TRANSACTIONS RELATED HERETO.

     30. ENVIRONMENTAL REQUIREMENTS.

<PAGE>

     (a) PROHIBITION/COMPLIANCE/INDEMNITY. Tenant shall not cause or permit any
Hazardous Materials (as hereinafter defined) to be brought upon, kept or used in
or about the Premises or the Project in violation of applicable law by Tenant,
its agents, employees, contractors or invitees. If Tenant breaches the
obligation stated in the preceding sentence, or if the presence of Hazardous
Materials in the Premises during the term of this Lease or Tenant's occupancy of
the Project results in contamination of the Premises, the Project or any
adjacent property or if contamination of the Premises, the Project or any
adjacent property by Hazardous Materials brought into the Premises by anyone
other than Landlord and Landlord's employees, agents and contractors otherwise
occurs during the term of this Lease or any extension or renewal hereof or
holding over hereunder, Tenant hereby indemnifies and shall defend and hold
Landlord, its officers, directors, employees, agents and contractors harmless
from any and all claims, judgments, damages, penalties, fines, costs,
liabilities, or losses (including, without limitation, diminution in value of
the Premises or any portion of the Project, damages for the loss or restriction
on use of rentable or usable space or of any amenity of the Premises or the
Project, damages arising from any adverse impact on marketing of space in the
Premises or the Project, and sums paid in settlement of claims, and reasonable
attorneys' fees, consultant fees and expert fees) which arise during or after
the Lease term as a result of such contamination. This indemnification of
Landlord by Tenant includes, without limitation, costs incurred in connection
with any investigation of site conditions or any cleanup, remedial, removal, or
restoration work required by any federal, state or local governmental agency or
political subdivision because of Hazardous Materials present in the air, soil or
ground water above, on, or under the Premises. Without limiting the foregoing,
if the presence of any Hazardous Materials on the Premises, the Project or any
adjacent property, caused or permitted by Tenant results in any contamination of
the Premises, the Project or any adjacent property, Tenant shall promptly take
all actions at its sole expense and in accordance with applicable law as are
necessary to return the Premises, the Project or any adjacent property, to the
condition existing as of the date hereof, provided that Landlord's approval of
such action shall first be obtained, which approval shall not unreasonably be
withheld so long as such actions would not potentially have any material adverse
long-term or short-term effect on the Premises or the Project.

     (b) BUSINESS. Landlord acknowledges that it is not the intent of this
Article 30 to prohibit Tenant from using the Premises for the Permitted Use.
Tenant may operate its business according to the custom of the industry so long
as the use or presence of Hazardous Materials is strictly and properly monitored
according to all applicable governmental requirements. As a material inducement
to Landlord to allow Tenant to use Hazardous Materials in connection with its
business, Tenant agrees to deliver to Landlord prior to the Commencement Date a
list identifying each type of Hazardous Materials to be present on the Premises
and setting forth any and all governmental approvals or permits required in
connection with the presence of such Hazardous Materials on the Premises
("HAZARDOUS MATERIALS LIST"). Tenant shall deliver to Landlord an updated
Hazardous Materials List at least once a year and shall also deliver an updated
list before any new Hazardous Material(s) is brought onto the Premises. Tenant
shall deliver to Landlord true and correct copies of the following documents
(the "HAZ MAT DOCUMENTS") relating to the handling, use, storage, disposal and
emission of Hazardous Materials prior to the Commencement Date, or if
unavailable at that time, concurrent with the receipt from or submission to a
governmental agency: permits; approvals; reports and correspondence; storage and
management plans, notice of violations of any laws; plans relating to the
installation of any storage tanks to be installed in or under the Project
(provided, said

<PAGE>

installation of tanks shall only be permitted after Landlord has given Tenant
its written consent to do so, which consent may be withheld in Landlord's sole
and absolute discretion); and all closure plans or any other documents required
by any and all federal, state and local governmental agencies and authorities
for any storage tanks installed in, on or under the Project for the closure of
any such tanks. Tenant is not required, however, to provide Landlord with any
portion(s) of the Haz Mat Documents containing information of a proprietary
nature which, in and of themselves, do not contain a reference to any Hazardous
Materials or hazardous activities. It is not the intent of this Section to
provide Landlord with information which could be detrimental to Tenant's
business should such information become possessed by Tenant's competitors.

     (c) TENANT REPRESENTATION AND WARRANTY. Tenant hereby represents and
warrants to Landlord that (i) neither Tenant nor any of its legal predecessors
has been required by any prior landlord, lender or governmental authority at any
time to take remedial action in connection with Hazardous Materials
contaminating a property which contamination was permitted by Tenant or such
predecessor or resulted from Tenant's or such predecessor's action or use of the
property in question, and (ii) Tenant is not subject to any enforcement order
issued by any governmental authority in connection with the use, disposal or
storage of a Hazardous Materials. If landlord determines that this
representation and warranty was not true as of the date of this lease, Landlord
shall have the right to terminate this Lease in Landlord's sole and absolute
discretion.

     (d) TESTING. Landlord shall have the right to conduct annual tests of the
Premises to determine whether any contamination has occurred as a result of
Tenant's use. Tenant shall be required to pay the cost of such annual test of
the Premises; provided, however, that if Tenant conducts its own tests of the
Premises using third party contractors and test procedures reasonably acceptable
to Landlord which tests are certified to Landlord, Landlord shall accept such
tests in lieu of the annual tests to be paid for by Tenant. In addition, at any
time, and from time to time, prior to the expiration or earlier termination of
the Term, Landlord shall have the right to conduct appropriate tests of the
Premises and the Project to determine if contamination has occurred as a result
of Tenant's use of the Premises. If contamination has occurred for which Tenant
is liable under this Section 30, Tenant shall pay all costs to conduct such
tests. If no such contamination is found, Landlord shall pay the costs of such
tests (which shall not constitute an Operating Expense). Landlord shall provide,
without representation or warranty and subject to a confidentiality agreement,
Tenant with a copy of all third party, non-confidential reports and tests of the
Premises made by or on behalf of Landlord. Tenant shall be solely responsible
for and shall defend, indemnify and hold Landlord, its agents and contractors
harmless from and against any and all claims, costs and liabilities including
actual attorneys' fees, charges and disbursement, arising out of or in
connection with any removal, clean up, restoration and materials required
hereunder to return the Premises and any other property of whatever nature to
their condition existing as of the date hereof. Landlord's receipt of or
satisfaction with any environmental assessment in no way waives any rights that
Landlord holds against Tenant.

     (e) UNDERGROUND TANKS. If underground or other storage tanks storing
Hazardous Materials located on the Premises are used by Tenant Or are hereafter
placed on the Premises by Tenant, Tenant shall monitor the storage tanks,
maintain appropriate records, implement reporting procedures, properly close any
underground storage tanks, and take or cause to be

<PAGE>

taken all other actions necessary or required under applicable state and federal
law, as such now exists or may hereafter be adopted or amended.

     (f) TENANT'S OBLIGATIONS. Tenant's obligations under this Article 30 shall
survive the expiration or earlier termination of the Lease. During any period of
time after the expiration or earlier termination of this Lease required by
Tenant or Landlord to complete the removal from the Premises of any Hazardous
Materials and the release and termination of any licenses or permits restricting
the use of the Premises, Tenant shall continue to pay the full Rent in
accordance with this Lease for any portion of the Premises not relet by Landlord
in Landlord's sole discretion, which Rent shall be prorated daily.

     (g) DEFINITIONS. As used herein, the term "Environmental Requirements"
means all applicable present and future statutes, regulations, ordinances,
rules, codes, judgments, orders or other similar enactments of any governmental
authority or agency regulating or relating to health, safety, or environmental
conditions on, under, or about the Premises or the environment, including
without limitation, the following: the Comprehensive Environmental Response,
Compensation and Liability Act; the Resource Conservation and Recovery Act; and
all state and local counterparts thereto, and any regulations or policies
promulgated or issued thereunder. As used herein, the term "Hazardous Materials"
means and includes any substance, material, waste, pollutant, or contaminant
listed or defined as hazardous or toxic, or regulated by reason of its impact or
potential impact on humans, animals and/or the environment under any
Environmental Requirements, asbestos and petroleum, including crude oil or any
fraction thereof, natural gas liquids, liquefied natural gas, or synthetic gas
usable for fuel (or mixtures of natural gas and such synthetic gas). As defined
in Environmental Requirements, Tenant is and shall be deemed to be the operator"
of Tenant's "facility" and the "owner" of all Hazardous Materials brought on the
Premises by Tenant, its agents, employees, contractors or invitees, and the
wastes, by-products, or residues generated, resulting, or produced therefrom.

     31. TENANT'S REMEDIES/LIMITATION OF LIABILITY. Landlord shall not be in
default hereunder unless Landlord fails to perform any of its obligations
hereunder within 30 days after written notice from Tenant specifying such
failure (unless such performance will, due to the nature of the obligation,
require a period of time in excess of 30 days, then after such period of time as
is reasonably necessary). Upon any default by Landlord, Tenant shall give notice
by registered or certified mail to any Holder of a Mortgage covering the
Premises and to any landlord of any lease of property in or on which the
Premises are located and Tenant shall offer such beneficiary, Holder and/or
landlord a reasonable opportunity to cure the default, including time to obtain
possession of the Project by power of sale or a judicial action if such should
prove necessary to effect a cure; provided Landlord shall have furnished to
Tenant in writing the names and addresses of all such persons who are to receive
such notices. All obligations of Landlord hereunder shall be construed as
covenants, not conditions; and, except as may be otherwise expressly provided in
this Lease, Tenant may not terminate this Lease for breach of Landlord's
obligations hereunder.

     All obligations of Landlord under this Lease will be binding upon Landlord
only during the period of its ownership of the Premises and not thereafter. The
term "Landlord" in this Lease shall mean only the owner, for the time being of
the Premises, and upon the transfer by such owner of its interest in the
Premises, such owner shall thereupon be released and discharged from

<PAGE>

all obligations of Landlord thereafter accruing, but such obligations shall be
binding during the Term upon each new owner for the duration of such owner's
ownership.

     32. INSPECTION AND ACCESS. Landlord and its agents, representatives, and
contractors may enter the Premises at any reasonable time to inspect the
Premises and to make such repairs as may be required or permitted pursuant to
this Lease and for any other business purpose. Landlord and Landlord's
representatives may enter the Premises during business hours on not less than 48
hours advance written notice (except in the case of emergencies in which case no
 .such notice shall be required and such entry may be at any time but Landlord
shall nonetheless be required to provide notice to Tenant of such emergency
entry as soon as practicable) for the purpose of effecting any such repairs,
inspecting the Premises, showing the Premises to prospective purchasers and,
during the last year of the Term, to prospective tenants or for any other
business purpose. Landlord may erect a suitable sign on the Premises stating the
Premises are available to let (within the last 9 months of the Term) or that the
Project is available for sale. Landlord may grant easements, make public
dedications, designate common areas and create restrictions on or about the
Premises, PROVIDED that no such easement, dedication, designation or restriction
materially, adversely affects Tenant's use or occupancy of the Premises for the
Permitted use. At Landlord's request, Tenant shall execute such instruments as
may be necessary for such easements, dedications or restrictions. Tenant shall
at all times, except in the case of emergencies, have the right to escort
Landlord or its agents, representatives, contractors or guests while the same
are in the Premises, provided such escort does not materially and adversely
affect Landlord's access rights hereunder.

     33. SECURITY. Tenant acknowledges and agrees that security devices and
services, if any, while intended to deter crime may not in given instances
prevent theft or other criminal acts and that Landlord is not providing any
security services with respect to the Premises. Tenant agrees that Landlord
shall not be liable to Tenant for, and Tenant waives any claim against Landlord
with respect to, any loss by theft or any other damage suffered or incurred by
Tenant in connection with any unauthorized entry into the Premises or any other
breach of security with respect to the Premises. Tenant shall be solely
responsible for the. personal safety of Tenant's officers, employees, agents,
contractors, guests and invitees while any such person is in, on or about the
Premises and/or the Project. Tenant shall at Tenant's cost obtain insurance
coverage to the extent Tenant desires protection against such criminal acts.

     34. FORCE MAJEURE. Except for the payment of Rent and Additional Rent,
neither Landlord nor Tenant shall be held responsible for delays in the
performance of their obligations hereunder when caused by strikes, lockouts,
labor disputes, weather, natural disasters, inability to obtain labor or
materials or reasonable substitutes therefor, governmental restrictions,
governmental regulations, governmental controls, delay in issuance of permits,
enemy or hostile governmental action, civil commotion, fire or other casualty,
and other causes beyond their reasonable control ("FORCE MAJEURE").

     35. BROKERS, ENTIRE AGREEMENT, AMENDMENT. Landlord and Tenant each
represent and warrant that it has not dealt with any broker, agent or other
person (collectively, "Broker) in connection with this transaction and that no
Broker brought about this transaction, other than the Broker, if any, set forth
on the first page of this Lease. Landlord and Tenant each hereby agree to
indemnify and hold the other harmless from and against any claims by any other
Broker

<PAGE>

claiming a commission or other form of compensation by virtue of having dealt
with Tenant or Landlord, as applicable, with regard to this leasing transaction.
This Lease may not be amended except by an instrument in writing signed by both
parties hereto.

     36. LIMITATION ON LANDLORD'S LIABILITY. NOTWITHSTANDING ANYTHING SET FORTH
HEREIN OR IN ANY OTHER AGREEMENT BETWEEN LANDLORD AND TENANT TO THE CONTRARY:
(A) LANDLORD SHALL NOT BE LIABLE TO TENANT OR ANY OTHER PERSON FOR (AND TENANT
AND EACH SUCH OTHER PERSON ASSUME ALL RISK OF) LOSS, DAMAGE OR INJURY, WHETHER
ACTUAL OR CONSEQUENTIAL TO: TENANT'S PERSONAL PROPERTY OF EVERY KIND AND
DESCRIPTION, INCLUDING, WITHOUT LIMITATION TRADE FIXTURES, EQUIPMENT, INVENTORY,
SCIENTIFIC RESEARCH, SCIENTIFIC EXPERIMENTS, LABORATORY ANIMALS, PRODUCT,
SPECIMENS, SAMPLES, AND/OR SCIENTIFIC, BUSINESS, ACCOUNTING AND OTHER RECORDS OF
EVERY KIND AND DESCRIPTION KEPT AT THE PREMISES AND ANY AND ALL INCOME DERIVED
OR DERIVABLE THEREFROM; (B) THERE SHALL BE NO PERSONAL RECOURSE TO LANDLORD FOR
ANY ACT OR OCCURRENCE IN, ON OR ABOUT THE PREMISES OR ARISING IN ANY WAY UNDER
THIS LEASE OR ANY OTHER AGREEMENT BETWEEN LANDLORD AND TENANT WITH RESPECT TO
THE SUBJECT MATTER HEREOF AND ANY LIABILITY OF LANDLORD HEREUNDER SHALL BE
STRICTLY LIMITED SOLELY TO LANDLORD'S INTEREST IN THE PROJECT, AND IN NO EVENT
SHALL ANY PERSONAL LIABILITY BE ASSERTED AGAINST LANDLORD IN CONNECTION WITH
THIS LEASE NOR SHALL ANY RECOURSE BE HAD TO ANY OTHER PROPERTY OR ASSETS OF
LANDLORD OR ANY OF LANDLORD'S OFFICERS, EMPLOYEES, AGENTS OR CONTRACTORS. UNDER
NO CIRCUMSTANCES SHALL LANDLORD OR ANY OF LANDLORD'S OFFICERS, EMPLOYEES, AGENTS
OR CONTRACTORS BE LIABLE FOR INJURY TO TENANT'S BUSINESS OR FOR ANY LOSS OF
INCOME OR PROFIT THEREFROM.

     37. SEVERABILITY. If any clause or provision of this Lease is illegal,
invalid or unenforceable under present or future laws, then and in that event,
it is the intention of the parties hereto that the remainder of this Lease shall
not be affected thereby. It is also the intention of the parties to this Lease
that in lieu of each clause or provision of this Lease that is illegal, invalid
or unenforceable, there be added, as a part of this Lease, a clause or provision
as similar in terms to such illegal, invalid or unenforceable clause or
provision as may be possible and be legal, valid and enforceable.

     38. SIGNS; EXTERIOR APPEARANCE. Tenant shall not, without the prior written
consent of Landlord, which may be granted or withheld in Landlord's sole
discretion: (i) attach any awnings, exterior lights, decorations, balloons,
flags, pennants, banners, painting or other projection to any outside wall of
the Project, (ii) use any curtains, blinds, shades or screens other than
Landlord's standard window coverings, (iii) coat or otherwise sunscreen the
interior or exterior of any windows, (iv) place any bottles, parcels, or other
articles on the window sills, (v) place any equipment, furniture or other items
of personal property on any exterior balcony, (vi) paint, affix or exhibit on
any part of the Premises or the Project any signs, notices, window or door
lettering, placards, decorations, or advertising media of any type which can be
viewed from the exterior of the Premises. interior signs on doors and the
directory tablet shall be inscribed,

<PAGE>

painted or affixed for Tenant by Landlord at the sole cost and expense of
Tenant, and shall be of a size, color and type acceptable to Landlord. Nothing
may be placed on the exterior of corridor walls or corridor doors other than
Landlord's standard lettering. The directory tablet shall be provided
exclusively for the display of the name and location of tenants.

     39. RIGHT TO EXTEND TERM. Tenant shall have the right to extend the Term of
the Lease upon the following terms and conditions:

     (a) EXTENSION RIGHT. Tenant shall have the right (an "EXTENSION RIGHT") to
extend the term of this Lease for 5 years (an "EXTENSION TERM") on the same
terms and conditions as this Lease by giving Landlord written notice of its
election to exercise such Extension Right at least 9 months prior to the
expiration of the Base Term of the Lease. Base Rent shall be adjusted on the
commencement date of the Extension Term and on each annual anniversary of the
commencement of the Extension Term by multiplying the Base Rent payable
immediately before such adjustment by the Rent Adjustment Percentage and adding
the resulting amount to the Base Rent payable immediately before such
adjustment. in addition, Landlord may impose a market rent for the parking
rights provided hereunder.

     (b) RIGHTS PERSONAL. The Extension Right is personal to Tenant and is not
assignable without Landlord's consent, which may be granted or withheld in
Landlord's sole discretion.

     (c) EXCEPTIONS. Notwithstanding anything set forth above to the contrary,
the Extension Right shall not be in effect and Tenant may not exercise the
Extension Right:

         (i) during any period of time that Tenant is in Default under any
provision of this Lease; or

         (ii) if Tenant has been in Default under any provision of this Lease 3
or more times, whether or not the Defaults are cured, during the 12 month period
immediately prior to the date that Tenant intends to exercise the Extension
Right, whether or not the Defaults are cured.

     (d) NO EXTENSIONS. The period of time within which the Extension Right may
be exercised shall not be extended or enlarged by reason of the Tenant's
inability to exercise the Extension Right.

     (e) TERMINATION. The Extension Right shall terminate and be of no further
force or effect even after Tenant's due and timely exercise of the Extension
Right, if, after such exercise, but prior to the commencement date of the
Extension Term, (i) Tenant fails to timely cure any default by Tenant under this
Lease; or (ii) Tenant has Defaulted 3 or more times during the period from the
date of the exercise of the Extension Right to the date of the commencement of
the Extension Term, whether or not such Defaults are cured.

     40. MISCELLANEOUS.

     (a) NOTICES. All notices or other communications between the parties shall
be in writing and shall be deemed duly given upon delivery or refusal to accept
delivery by the addressee thereof if delivered in person, or upon actual receipt
if delivered by reputable overnight guaranty courier, addressed and sent to the
parties at their addresses set forth above.

<PAGE>

Landlord and Tenant may from time to time by written notice to the other
designate another address for receipt of future notices.

     (b) JOINT AND SEVERAL LIABILITY. If and when included within the term
"Tenant," as used in this instrument, there is more than one person or entity,
each shall be jointly and severally liable for the obligations of Tenant.

     (c) FINANCIAL INFORMATION. Tenant shall furnish Landlord with true and
complete copies of (i) Tenant's most recent unaudited annual financial
statements within 90 days of the end of each of Tenant's fiscal years during the
Term and the audited annual financial statement within 180 days of the end of
Tenant's fiscal years during the Term, (ii) Tenant's most recent unaudited
quarterly financed statements within 45 days of the end of each of Tenant's
fiscal quarters during the Term, (iii) at Landlord's request from time to time,
updated business plans, including cash flow projections and/or pro forma balance
sheets and income statements, all of which shall be treated by Landlord as
confidential information belonging to Tenant, (iv) corporate brochures and/or
profiles prepared by Tenant for prospective investors, and (v) any other
financial information or summaries that Tenant typically provides to its lenders
or shareholders.

     (d) RECORDATION. Neither this Lease nor a memorandum of lease shall be
filed by or on behalf of Tenant in any public record. Landlord may prepare and
file, and upon request by Landlord Tenant will execute, a memorandum of lease.

     (e) INTERPRETATION. The normal rule of construction to the effect that any
ambiguities are to be resolved against the drafting party shall not be employed
in the interpretation of this Lease or any exhibits or amendments hereto. Words
of any gender used in this Lease shall be held and construed to include any
other gender, and words in the singular number shall be held to include the
plural, unless the context otherwise requires. The captions inserted in this
Lease are for convenience only and in no way define, limit or otherwise describe
the scope or intent of this Lease, or any provision hereof, or in any way affect
the interpretation of this Lease.

     (f) NOT BINDING UNTIL EXECUTED. The submission by Landlord to Tenant of
this Lease shall have no binding force or effect, shall not constitute an option
for the leasing of the Premises, nor confer any right or impose any obligations
upon either party until execution of this Lease by both parties.

     (g) LIMITATIONS ON INTEREST. It is expressly the intent of Landlord and
Tenant at all times to comply with applicable law governing the maximum rate or
amount of any interest payable on or in connection with this Lease. If
applicable law is ever judicially interpreted so as to render usurious any
interest called for under this Lease, or contracted for, charged, taken,
reserved, or received with respect to this Lease, then it is Landlord's and
Tenant's express intent that all excess amounts theretofore collected by
Landlord be credited on the applicable obligation (or, if the obligation has
been or would thereby be paid in full, refunded to Tenant), and the provisions
of this Lease immediately shall be deemed reformed and the amounts thereafter
collectible hereunder reduced, without the necessity of the execution of any new
document, so as to comply with the applicable law, but so as to permit the
recovery of the fullest amount otherwise called for hereunder.

<PAGE>

     (h) CHOICE OF LAW. Construction and interpretation of this Lease shall be
governed by the internal laws of the state in which the Premises are located,
excluding any principles of conflicts of laws.

     (i) TIME. Time is of the essence as to the performance of the parties'
obligations under this Lease.

     (j) INCORPORATION BY REFERENCE. All exhibits and addenda attached hereto
are hereby incorporated into this Lease and made a part hereof. If there is any
conflict between such exhibits or addenda and the terms of this Lease, such
exhibits or addenda shall control.

                            [Signature Page Follows)

     IN WITNESS WHEREOF, Landlord and Tenant have executed this Lease as of the
day and year first above written.

                                    TENANT:

                                    t.BREEDERS, INC., a Delaware corporation

                                    By: Signature on File
                                        -------------------------------------
                                    Its: President
                                        -------------------------------------

                                    LANDLORD:

                                    ARE-ONE INNOVATION DRIVE, LLC,
                                    a Delaware limited liability company

                                    By:  AREE-Holdings, L.P., a Delaware limited
                                         partnership, its managing member

                                         By:  ARE-GP Holdings QRS Corp., a
                                              Delaware corporation, its general
                                              partner

                                    By: /s/ Lynne Anne Shapiro
                                        -------------------------------------

                                    Its: General Counsel
                                        -------------------------------------

         [Notary seal]

<PAGE>

                               EXHIBIT B TO LEASE

                             DESCRIPTION OF PROJECT

<PAGE>

                                 QUITCLAIM DEED

     WALDO CORPORATION, a corporation duly established under the laws of
Massachusetts and having a usual place of business at 33 Waldo Street,
Worcester, Worcester County, Massachusetts, as Trustee of Three Biotech Realty
Trust under Declaration of Trust dated September 8, 1995 and recorded with the
Worcester District Registry of Deeds in Book 17323, Page 157, for consideration
paid and in full consideration of $16,500,000 grants to ARE-ONE INNOVATION
DRIVE, LLC, a limited liability company duly, established under the laws of
Delaware and having a usual place of business at 135 N. Los Robles Avenue, Suite
250, Pasadena, Los Angeles County, California

                            WITH QUITCLAIM COVENANTS

     the following two (2) parcels of land:

     PARCEL 1

     The land with the building thereon in Worcester, Worcester County,
Massachusetts consisting of Area A containing 2.7893 acres, more or less, Area B
containing 5.6169 acres, more or less, and a portion of Innovation Drive
containing 17,361 square feet, more or less, all as shown on a plan entitled
"Plan of Property Owned by Worcester Business Development Corporation, Three
Biotech Park, Off Plantation Street, Worcester, Massachusetts" dated January 31,
1990, prepared by Cullinan Engineering Co., Inc. and recorded with the Worcester
District Registry of Deeds (the "Registry") in Plan Book 633, Plan 79 (the
"Parcel I Plan"), bounded and described as follows:

     BEGINNING at the most northerly corner of the Premises at the intersection
of the southerly line 2 of land now or formerly of The Commonwealth of
Massachusetts and the westerly line of other o land now or formerly of Worcester
Business Development Corporation ("WBDC") as shown on the Parcel I Plan;

     THENCE S. 07 DEG. 38' 43" E. one hundred thirty-eight and 71/100 (138.71)
feet by WBDC land and land shown on the Parcel I Plan as Two Biotech Park to a
point;

     THENCE S. 00 DEG. 45' 00" W. two hundred fifty and 45/100 (250.45) feet
by Two Biotech Park to a point;

     THENCE S. 04 DEG. 12' 20" W. one hundred ninety-five and 54/100 (195.54)
feet by Two Biotech Park to a point;

     THENCE S. 04 DEG. 04' 59" W. seventy (70) feet by Two Biotech Park and land
shown on the Parcel I Plan as C.M.M.I.C. Parcel to a point;

     THENCE S. 18 DEG. 32' 25" W. one hundred eighty-seven and 62/100 (187.62)
feet by C.M.M.I.C. Parcel to a point at land shown on the Parcel I Plan as One
Biotech Park;

<PAGE>

     THENCE N. 67 DEG. 02' 30" W. nineteen and 33/100 (19.33) feet by One
Biotech Park to a point;

     THENCE S. 81 DEG. 31' 00" W. eighty (80) feet by One Biotech Park to a
point at other land now or formerly of WBDC;

     THENCE N. 89 DEG. 43' 26" W. one hundred forty and 03/100 (140.03) feet by
land now or formerly of WBDC to a point at the roadway easement, Innovation
Drive, shown on the Parcel I Plan;

     THENCE N. 64 DEG. 42' 20" W. fifty (50) feet across Innovation Drive to a
point;

     THENCE 48 DEG. 20' 06" W. three hundred ninety-six and 74/100 (396.74)
feet by WBDC land to a point at land shown on the Parcel I Plan as B.A.S.F.
Parcel;

     THENCE N. 30 DEG. 42' 12" W. two hundred fifty-five and 04/100 (255.04)
feet by B.A.S.F. Parcel to a point at The Commonwealth of Massachusetts land;

     THENCE N. 63 DEG. 33' 40" E. twenty and 06/100 (20.06) feet to a point;

     THENCE N. 40 DEG. 43' 36" E. two hundred sixteen and 21/100 (216.21) feet
to a point;

     THENCE N. 49 DEG. 56' 15" E. three hundred fifty (350) feet to a point;

     THENCE by a curve to the left having a radius of 225.00 feet and an arc
distance of three hundred thirty-seven and 01/100 (337.01) feet to a point;

     THENCE N. 67 DEG. 21' 00" E. three hundred ninety-nine and 15/100 (399.15)
feet to the point of beginning, the last five courses being by The Commonwealth
of Massachusetts land.

     CONTAINING 8.8048 acres, more or less, according to the Parcel I Plan. Area
A and Area B shown on the Plan are the same parcels shown as Parcel 7B and
Parcels 7A, respectively, on a plan entitled "Amended Definitive Subdivision
Plan for Worcester Business Development Corporation, Belmont Street (Route 9) &
Plantation Street, Worcester, Massachusetts" dated January 3, 1990 prepared by
Maguire Group, Inc. and Cullinan Engineering Co., Inc. recorded at the Registry
in Plan Book 633, Plan 78 ("Amended Subdivision Plan").

     The premises are conveyed subject to and together with the following
rights, easements, benefits and appurtenances:

     1. Easements in common with others to use, for all public way purposes,
Research Drive (shown as "RE-1"), Innovation Drive (shown as "RE-2") and Roadway
Easement 3 (shown as "RE-3") on the Amended Subdivision Plan.

     2. An easement in common with others to use, for all public way purposes,
Easement Areas "A" and "B" which are described in the deed from The Commonwealth
of Massachusetts, acting by and through its Division of Capital Planning and
Operations, to WBDC dated June 13, 1984 and recorded at the Registry in Book
8233, Page 106.

<PAGE>

     3. An easement in common with others to use for all public way purposes,
Easement "C", as shown on the Amended Subdivision Plan.

     4. Rights in common with others to use for their intended purposes those
Utility Easements which service the Premises shown on the Amended Subdivision
Plan.

     5. Provisions of a Declaration of Easement by Worcester Business
Development Corporation dated March 27, 1990 and recorded with the Registry in
Book 12717, Page 3, as modified by an Amendment dated August 24, 1992 and
recorded with the Registry in Book 14471, Page 357.

     6. The provisions of Variance Decision by the Worcester Zoning Board of
Appeals recorded at the Registry in Book 12556, Page 319.

     7. Reservations, restrictions, covenants, conditions, terms and provisions
set forth or referred to in the deed from The Commonwealth of Massachusetts,
acting by and through its Division of Capital Planning and Operations, to WBDC
dated June 13, 1984 and recorded with the Registry in Book 8233, Page 106.

     8. Rights of others in Innovation Drive (shown as "RE-2") on a plan
recorded with the Registry in Plan Book 633, Plan 78 and rights in the areas
shown as "UE-13", "UE-16", UE-18" and "UE-20" on said Plan, all as recited in a
Deed of Easement from WBDC to City of Worcester dated April 30, 1990 and
recorded with the Registry in Book 12860, Page 123.

     9. The grading and drainage easement for the benefit of the land known as
"One Biotech Parcel" shown on a plan recorded with the Registry in Plan Book
550, Plan 12.

     10. Rights reserved by WBDC in its deed to Waldo Corporation, as Trustee of
Three Biotech Realty Trust, to use, maintain, repair, replace, relocate all
existing pipes, lines, manholes and other apparatus for sewer and drainage
purposes, and to grant those rights to others, provided that any relocation will
not interfere with the development or use of the Premises, and any surface which
is disturbed will be restored as near as possible to its original condition, as
recited in the deed from WBDC to Massachusetts Biotechnology Research Institute,
Inc. dated July 20, 1990 and recorded with the Registry in Book 12905, Page 393.

     11. Provisions of a Declaration of Protective Covenants, Conditions and
Restrictions by WBDC dated June 26, 1990 and recorded with the Registry in Book
12860, Page 145.

     12. Order of Taking by the City of Worcester from WBDC to make Innovation
Drive public dated April 13, 1993 and recorded with the Registry in Book 15379,
Page 215.

     13. Rights in areas shown as "UE-22", "UE-23" and "UE-24" on a plan
recorded with the Registry in Plan Book 696, Page 87 granted to the City of
Worcester and The Commonwealth of Massachusetts by the Massachusetts
Biotechnology Research Institute, Inc. in an instrument dated September 22, 1995
and recorded in Book 17343, Page 96.

     14. Security Agreement and Mortgage Deed from Massachusetts Biotechnology
Research Institute, Inc. (as Ground Lessor) and Waldo Corporation, as Trustee of
Three Biotech

<PAGE>

Realty Trust (as Ground Lessee) to Teachers Insurance and Annuity Association of
America for $14,360,000.00 dated December 20, 1995 and recorded with the
Registry in Book 17557, Page 387, with a outstanding balance of $11,297,144.47,
which the Grantee hereby assumes and agrees to pay.

     See deed to Waldo Corporation, as Trustee of Three Biotech Realty Trust,
from Massachusetts Biomedical Research Initiatives, Inc. dated January 6, 1999,
and recorded herewith.

PARCEL II

Parcel of land in The Commonwealth of Massachusetts, County of Worcester, City
of Worcester on the westerly side of Innovation Drive owned by Worcester
Business Development Corporation and shown as Parcel 4 on a plan by Cullinan
Engineering Co., Inc. titled 'Plan of Property -- Worcester, Mass." and dated
July 6, 1998 and recorded with the Worcester District Registry of Deeds in Plan
Book 736, Page 54 ("Parcel II Plan") and bounded and described as follows:

BEGINNING at a point of tangency on the westerly sideline of Innovation Drive at
the most northerly corner of the parcel to be described; said point being N
64 DEG. 42' 20" W and 2.00 feet from a Worcester Highway Bound;

THENCE along the westerly sideline of Innovation Drive the following three (3)
courses:

S 25 DEG. 17' 40" W, a distance of 212.23 feet to a point of curvature;

In a southerly direction by a curve to the left, having a radius of 500.00 feet,
an are distance of 402.55 feet to a point of tangency;

AND S. 20 DEG. 50' 05" E., a distance of 3.29 feet to a point at land now or
formerly of BASF Bioresearch Corp:;

THENCE N. 30 DEG. 42' 12" W along land now or formerly of BASF Bioresearch
Corp., a distance of 375.30 feet to a point at other land now or formerly of
Worcester Business Development Corporation;

THENCE N. 48 DEG. 20' 06" E. along land now or formerly of Worcester Business
Development Corporation, a distance of 396.74 feet to the Point of Beginning;

CONTAINING 1.0508 acres, more or less according to the Parcel II Plan.

Also including the fee interest in that portion of Innovation Drive abutting the
above-described Parcel II, to the center line of Innovation Drive.

The premises are conveyed subject to and together with the following rights,
easements, benefits and appurtenances:

<PAGE>

     1. Easements in common with others to use, for all public way purposes,
Research Drive (shown as "RE-i"), Innovation Drive (shown as "RE-2") and Roadway
Easement 3 (shown as "RE-3") on the Amended Subdivision Plan.

     2. An easement in common with others to use, for all public way purposes,
Easement Areas "A" and "B" which are described in the deed from the The
Commonwealth of Massachusetts, acting by and through its Division of Capital
Planning and Operations, to WBDC dated June 13, 1984 and recorded at the
Registry in Book 8233, Page 106.

     3. An easement in common with others to use for all public way purposes,
Easement "C", as shown on the Amended Subdivision Plan.

     4. Rights in common with others to use for their intended purposes those
Utility Easements which service the Premises shown on the Amended Subdivision
Plan.

     5. Restrictions and other provisions of a deed from The Commonwealth of
Massachusetts to Worcester Business Development Corporation dated June 13, 1984
and recorded with the Registry in Book 8233, Page 106.

     6. Rights of the City of Worcester under a deed of easements from Worcester
Business Development Corporation dated April 30, 1990 and recorded with the
Registry in Book 12860, Page 123.

     7. Provisions of a Declaration of Protective Covenants, Conditions and
Restrictions by Worcester Business Development Corporation dated June 26, 1990
and recorded with the Registry in Book 12860, Page 145.

     8. Rights of others in "Proposed UE-19" shown on plan recorded with the
Registry in Plan Book 633, Plan 78.

     9. Order of Taking from Worcester Business Development Corporation by the
City of Worcester for Innovation Drive recorded with the Registry in Book 15379,
Page 215.

     See deed to Waldo Corporation, as Trustee of Three Biotech Realty Trust,
from Worcester Business Development Corporation dated January 15, 1999 and
recorded herewith.

     The premises conveyed hereby are not all, or substantially all, of the
property of Waldo Corporation, as Trustee of Three Biotech Realty Trust, and
Worcester Business Development Corporation in The Commonwealth of Massachusetts.

     [THIS SPACE INTENTIONALLY LEFT BLANK]

<PAGE>

                               EXHIBIT C TO LEASE
                                [LANDLORD BUILD]

                                   WORK LETTER

     THIS WORK LETTER dated Feb. 24, 2000 (this "Work Letter") is made and
entered into by and between ARE-ONE INNOVATION DRIVE, LLC, a Delaware limited
liability company ("Landlord"), and t.BREEDERS, INC., a Delaware Corporation
("Tenant"), and is attached to and made a part of the Lease dated Feb. 24, 2000
(the "Lease"), by and between Landlord and Tenant. Any initially capitalized
terms used but not defined herein shall have the meanings given them, in the
Lease.

     1. GENERAL REQUIREMENTS

     (a) TENANT'S AUTHORIZED REPRESENTATIVE. Tenant designates Mr. Morey Kraus
("TENANT'S Representative") as the only person authorized to act for Tenant
pursuant to this Work Letter. Landlord shall not be obligated to respond to or
act upon any request, approval, inquiry or other communication ("COMMUNICATION")
from or on behalf of Tenant in connection with this Work Letter unless such
Communication is in writing from Tenant's Representative. Tenant may change
Tenant's Representatives at any time upon not less than 5 business days advance
written notice to Landlord. No period set forth herein for any approval of any
matter by Tenant's Representative shall be extended by reason of any change in
Tenant's Representative. Neither Tenant nor Tenant's Representative shall be
authorized to direct Landlord's contractors in the performance of Landlord's
Work (as hereinafter defined).

     (b) LANDLORD'S AUTHORIZED REPRESENTATIVE. Landlord designates Mr. Tom
Andrews and Mr. Albert Cleef (either such individual acting alone, "Landlord's
Representative") as the only persons authorized to act for Landlord pursuant to
this Work Letter. Tenant shall not be obligated to respond to or act upon any
request, approval, inquiry or other Communication from or on behalf of Landlord
in connection with this Work Letter unless such Communication is in writing from
Landlord's Representative. Landlord may change Landlord's Representatives at any
time upon not less than 5 business days advance written notice to Tenant. No
period set forth herein for any approval of any matter by Landlord's
Representative shall be extended by reason of any change in Landlord's
Representative. Landlord's Representative shall be the sole persons authorized
to direct Landlord's contractors in the performance of Landlord's Work.

     (c) DEVELOPMENT SCHEDULE. The schedule for design and development of the
Tenant Improvements (as defined below), including without limitation the time
periods for delivery of construction documents and performance, shall be in
accordance with the Development Schedule attached hereto as Schedule A, subject
to adjustment as mutually agreed by the parties in writing or as provided in
this Work Letter (the "DEVELOPMENT SCHEDULE").

     (d) ARCHITECTS, CONSULTANTS AND CONTRACTORS. Landlord and Tenant hereby
acknowledge and agree that the architect for the Tenant Improvements shall be
Arch Design, Inc. (the "TI ARCHITECT"), and the general contractor shall be
Richmond Group, Inc., and any subcontractors for the Tenant Improvements shall
be selected by Landlord, subject to Tenant's approval, which approval shall not
be unreasonably withheld, conditioned or delayed.

<PAGE>

     2. TENANT IMPROVEMENTS.

     (a) TENANT IMPROVEMENTS DEFINED. As used herein, "Tenant Improvements"
shall mean all improvements to the Project desired by Tenant of a fixed and
permanent nature as depicted on the TI Construction Drawings (defined below).
Other than the Tenant Improvements and recarpeting and repainting of offices as
shown on the plan attached hereto as Schedule B, Landlord shall not have any
obligation whatsoever with respect to the finishing of the Premises for Tenant's
use and occupancy.

     (b) TENANT'S SPACE PLANS. Landlord and Tenant acknowledge and agree that
the TI Architect schematic drawings and outline specifications (the "TI Design
Drawings") detailing Tenant's requirements for the Tenant Improvements have all
already been submitted by Tenant and approved by Landlord.

     (c) WORKING DRAWINGS. Not later than ten (10) business days following
execution of the Lease, Landlord shall cause the Tl Architect to prepare and
deliver to Tenant for review and comment construction plans, specifications and
drawings for the Tenant Improvements ("TI Construction Drawings"), which TI
Construction Drawings shall be prepared substantially in accordance with the
preliminary plans and specifications for development of the Tenant Improvements
(the "Preliminary TI Plans") which Tenant acknowledges having already reviewed
and approved. Tenant shall be solely responsible for ensuring that the TI
Construction Drawings reflect Tenant's requirements for the Tenant Improvements.
Tenant shall deliver its written comments on the TI Construction Drawings to
Landlord not later than five (5 business days after Tenant's receipt of the
same; provided, however, that Tenant may not disapprove any matter that is
consistent with the Preliminary TI Plans without submitting a Change Request.
Landlord and the TI Architect shall consider all such comments in good faith and
shall, within five (5) business days after receipt, notify Tenant how Landlord
proposes to respond to such comments, but Tenant's review rights pursuant to the
foregoing sentence shall not delay the design or construction schedule for the
Tenant Improvements. Any disputes in connection with such comments shall be
resolved in accordance with Section 2(d) hereof. Provided that the design
reflected in the TI Construction Drawings is consistent with the Preliminary TI
Plans approved by Tenant, Tenant shall approve the TI Construction Drawings
submitted by Landlord, unless Tenant submits a Change Request. Once approved by
Tenant, subject to the provisions of Section 2(d) below, Landlord shall not
materially modify the TI Construction Drawings except as may be reasonably
required in connection with the issuance of the TI Permit.

     (d) APPROVAL AND COMPLETION. Upon any dispute regarding the design of the
Tenant Improvements, which is not settled within five (5) business days after
notice of such dispute is delivered by one party to the other, Tenant shall make
the final decision regarding the design of the Tenant Improvements, provided
Tenant acts reasonably and such final decision is either consistent with or a
compromise between Landlord's and Tenant's positions with respect to such
dispute, provided further that all costs and expenses resulting from any such
decision by Tenant shall be payable out of the TI Fund, as defined in Section
5(d) below. Any changes to the Tl Construction Drawings following Landlord's and
Tenant's approval of same requested by Tenant shall be processed as provided in
Section 4 hereof.

<PAGE>

     3. PERFORMANCE OF LANDLORD'S WORK.

     (a) DEFINITION OF LANDLORD'S WORK. As used herein, "Landlord's Work" shall
mean the work of constructing the Tenant Improvements.

     (b) COMMENCEMENT AND PERMITTING OF LANDLORD'S WORK. Landlord shall commence
construction of the Tenant Improvements upon obtaining a building permit (the
"TI Permit") authorizing the construction of the Tenant Improvements consistent
with the TI Construction Drawings approved by Tenant. The cost of obtaining the
TI Permit shall be payable from the TI Fund. Tenant shall assist Landlord in
obtaining the TI Permit. If any Governmental Authority having jurisdiction over
the construction of Landlord's Work or any portion thereof shall impose terms or
conditions upon the construction thereof which: (i) are inconsistent with
Landlord's obligations hereunder, (ii) increase the cost of constructing
Landlord's Work, or (iii) will materially delay the construction of Landlord's
Work, Landlord and Tenant shall reasonably and in good faith seek means by which
to mitigate or eliminate any such adverse terms and conditions.

     (c) COMPLETION OF LANDLORD'S WORK. Landlord shall substantially complete or
cause to be substantially completed Landlord's Work in a good and workmanlike
manner using materials reasonably acceptable to the TI Architect, in accordance
with the TI Permit subject to Minor Variations and normal "punch list" items of
a non-material nature which do not interfere with the use of the Premises
("Substantial Completion"). Upon the Substantial Completion of Landlord's Work,
Landlord shall require the TI Architect and the general contractor to execute
and deliver, for the benefit of Tenant and Landlord, a Certificate of
Substantial Completion in the form of the American Institute of Architects
document G704. For purposes of this Work Letter, "Minor Variations" shall mean
any modifications reasonably required: (i) to comply with all applicable Legal
Requirements and for to obtain or to comply with any required permit (including
the TI Permit); (ii) to comply with any request by the Tenant for modifications
to Landlord's Work; (iii) to comport with good design, engineering, and
construction practices which are not material; or (iv) to make reasonable
adjustments for field deviations or conditions encountered during the
construction of Landlord's Work.

     (d) SELECTION OF MATERIALS, ETC. Where more than one type of material or
structure is indicated on the Tl Construction Drawings approved by Landlord and
Tenant, the option will be within Landlord's sole discretion. As to all building
materials and equipment which Landlord is obligated to supply under this Work
Letter, Landlord shall select the manufacturer thereof in its sole discretion.

     (e) ACCEPTANCE OF LANDLORD'S WORK. When Landlord's Work is Substantially
Complete, subject to the remaining terms and provisions of this Section 3(e),
Tenant shall accept such work. Tenant's acceptance of Landlord's Work shall not
constitute a waiver of: (i) any warranty with respect to workmanship (including
installation of equipment) or material (exclusive of equipment provided directly
by manufacturers) (ii) any non-compliance of Landlord's Work with Code, or (iii)
any claim that Landlord's Work was not completed substantially in accordance
with the TI Construction Drawings (subject to Minor Variations and such other
changes as are permitted hereunder) (collectively, a "Construction

<PAGE>

Defect"). Tenant shall have one (1) year after Substantial Completion within
which to notify Landlord of any such Construction Defect discovered by Tenant,
and Landlord shall use reasonable efforts to remedy or cause the responsible
contractor to remedy any such Construction Defect within thirty (30) days
thereafter. Notwithstanding the foregoing, Landlord shall not be in default
under the Lease if the applicable contractor, despite Landlord's reasonable
efforts, fails to remedy such Construction Defect within such thirty (30) day
period, in which case Landlord shall have no further obligation with respect to
such Construction Defect other than to cooperate, at no cost to Landlord, with
Tenant should Tenant elect to pursue a claim against such contractor, provided
that Tenant indemnifies and holds Landlord harmless from and against any
liability, loss, cost damage or expense in connection with any such claim.

     Upon written request from Tenant, Landlord agrees, at no cost to Landlord
and subject to the indemnity and hold harmless in the preceding sentence, to
execute such documents as may be reasonably requested by Tenant in order that
Tenant may pursue a claim directly or, if Landlord consents, in Landlord's name
against the responsible contractor in connection with a Construction Defect.
Tenant shall be entitled to receive the benefit of all construction warranties
and manufacturer's equipment warranties relating to equipment installed in the
Premises. If requested by Tenant, Landlord shall attempt to obtain extended
warranties from manufacturers and suppliers of such equipment, but the cost of
any such extended warranties shall be borne solely out of the TI Fund. Landlord
shall diligently pursue any claims arising out of latent defects in the
Building. Landlord shall promptly undertake and complete, or cause to be
completed, all punch list items.

     (f) RENT INCREASE DATE. The Rent Increase Date shall occur when Landlord's
Work has been Substantially Completed, except to the extent that completion of
Landlord's Work shall have been actually delayed by any one or more of the
following causes (a "Tenant Delay"):

         (i) Tenant's Representative was not available to give or receive any
     Communication or to take any other action required to be taken by Tenant
     hereunder;

         (ii) Tenants request for Change Requests whether or not any such Change
     Requests are actually performed;

         (iii) Construction of any Change Requests;

         (iv) Tenant's request for materials, finishes or installations
     requiring unusually long lead times;

         (v) Tenant's delay in reviewing, revising or approving plans and
     specifications beyond the periods set forth herein;

         (vi) Tenant's delay in providing information critical to the normal
     progression of the Project. Tenant shall provide such information as soon
     as reasonably possible, but in no event longer than one week after receipt
     of any request for such information from Landlord;

         (vii) Tenant's delay in making payments to Landlord for Excess TI
     Costs; or

<PAGE>

         (viii) Any other act or omission by Tenant, its agents, contractors or
     persons employed by any of such persons.

         If the Rent Increase Date is delayed for any of the foregoing reasons,
     then Landlord shall cause the TI Architect to certify the date on which the
     Tenant Improvements would have been completed but for such Tenant Delay and
     such certified date shall be the Rent Increase Date under the Lease.

     4. CHANGES. Any changes requested by Tenant to the Tenant Improvements
after the delivery and approval by Landlord of the TI Design Drawings, shall be
requested and instituted in accordance with the provisions of this Section 4 and
shall be subject to the written approval of Landlord and the TI Architect, such
approval not to be unreasonably withheld, conditioned or delayed.

     (a) TENANT'S RIGHT TO REQUEST CHANGES. If Tenant shall request changes to
Landlord's Work ("CHANGES"), Tenant shall request such Changes by notifying
Landlord in writing in substantially the same form as the AlA standard change
order form (a "Change Major Construction - Landlord Build, One Innovation
Drive/t.Breeders, Inc. Page 5 Request"), which Change Request shall detail the
nature and extent of any such Change. Such Change Request must be signed by
Tenant's Representative. Landlord shall, before proceeding with any Change, use
its best efforts to respond to Tenant as soon as is reasonably possible with an
estimate of: (i) the time it will take, and (ii) the architectural and
engineering fees and costs which will be incurred, to analyze such Change
Request (which costs shall be paid from the TI Fund to the extent actually
incurred, whether or not such change is implemented). Landlord shall thereafter
submit to Tenant in writing, within five (5)) business days of receipt of the
Change Request (or such longer period of time as is reasonably required
depending on the extent of the Change Request), an analysis of the additional
cost or savings involved, including, without limitation architectural and
engineering costs and the period of time, if any, that the Change will extend
the date on which Landlord's Work will be Substantially Complete. Any such delay
in the completion of Landlord's Work caused by a Change, including any
suspension of Landlord's Work while any such Change is being evaluated and/or
designed, shall be a Tenant Delay.

     (b) IMPLEMENTATION OF CHANGES. If Tenant: (i) approves in writing the cost
or savings and the estimated extension in the time for completion of Landlord's
Work, if any, and (ii) deposits with Landlord any Excess TI Costs (as defined
below) required in connection with such Change, Landlord shall cause the
approved Change to be instituted. Notwithstanding any approval or disapproval by
Tenant of any estimate of the delay caused by such proposed Change, the TI
Architect's determination of the Tenant Delay in connection with such Change
shall be final and binding on Landlord and Tenant.

     5. COSTS.

     (a) BUDGET FOR TENANT IMPROVEMENTS. Before the commencement of construction
of the Tenant Improvements, Landlord shall obtain a detailed breakdown, by
trade, of the costs incurred or which will be incurred, in connection with the
design and construction of Tenant's Work (the "Budget"). The Budget shall be
based upon the TI Construction Drawings approved by Tenant and shall include a
payment to Landlord, of administrative rent equal ("Administrative

<PAGE>

Rent") to 5% of the TI Costs (as hereinafter defined) for monitoring and
inspecting the construction of Tenant's Work, which sum shall be payable from
the TI Fund. Such Administrative Rent shall include, without limitation, all
out-of-pocket costs, expenses and fees incurred by or on behalf of Landlord
arising from, out of, or in connection with, such monitoring of the construction
of the Tenant's Improvements, and shall be payable out of the TI Fund. If the
Budget is greater than the TI Allowance, Tenant shall deposit with Landlord the
difference, in cash, prior to the commencement of construction of the Tenant
Improvements, for disbursement by Landlord as described in Section 5(d).

     (b) TI ALLOWANCE. Landlord shall provide to Tenant a tenant improvement
allowance ("TI Allowance") of $400,000. The TI Allowance shall be disbursed in
accordance with this Work Letter.

     (c) COSTS INCLUDABLE IN TI FUND. The TI Fund shall be used solely for the
payment of design and construction costs in connection with the construction of
the Tenant Improvements, including, without limitation, the cost of preparing
the Tl Design Drawings, the Preliminary TI Plans, and the TI Construction
Drawings, all costs set forth in the Budget, including Landlord's Administrative
Rent, costs resulting from Tenant Delays and the cost of Changes (collectively,
"TI Costs"). Notwithstanding anything to the contrary contained herein, the TI
Fund shall not be used to purchase any furniture, personal property or other
non-building system materials or equipment, including, but not be limited to,
biological safety cabinets and other scientific equipment not incorporated into
the Improvements.

     (d) EXCESS TI COSTS. It is understood and agreed that Landlord is under no
obligation to bear any portion of the cost of any of the Tenant Improvements
except to the extent of the TI Allowance. If at any time and from time-to-time,
the remaining TI Costs under the Budget exceed the remaining unexpended TI
Allowance, Tenant shall deposit with Landlord, as a condition--precedent to
Landlord's obligation to complete the Tenant Improvements, 100% of the then
current TI Cost in excess of the remaining TI Allowance ("Excess TI Costs"). If
Tenant fails to deposit, or is late in depositing, any Excess TI Costs amount
with Landlord, Landlord shall have all of the rights and remedies set forth in
the Lease for nonpayment of Rent (including, but not limited to, the right to
interest at the Default Rate and the right to assess a late charge), and for
purposes of any litigation instituted with regard to such amounts the, same will
be considered Rent, Such deposit of Excess TI Costs, together with the remaining
11 Allowance, is herein referred to as the "Tl Fund". Funds so deposited by
Tenant shall be the first thereafter disbursed to pay TI Costs. Notwithstanding
anything to the contrary set forth in this Section 5(d), Tenant shall be fully
and solely liable for TI Costs and the cost of Minor Variations in excess of the
TI Allowance. If upon Substantial Completion of the Tenant Improvements and the
payment of all sums due in connection therewith there remains any undisbursed Ti
Fund, Tenant shall be entitled to such undisbursed TI Fund solely to the extent
of any Excess TI Costs deposit Tenant has actually made with Landlord.

     6. TENANT ACCESS. Entry by Tenant into the Premises shall comply with all
established safety practices of Landlord's contractor and Landlord until
completion of Landlord's Work and acceptance thereof by Tenant. Neither Tenant
nor its employees, consultants, agents, contractors, and suppliers shall
interfere with the performance of Landlord's Work, nor with any inspections or
issuance of final approvals by the City of Worcester, and upon

<PAGE>

any such interference, Landlord shall have the right to exclude Tenant and
Tenant's employees, consultants, contractors and agents from the Premises and
the Building until Substantial Completion of Landlord's Work. Tenant shall
indemnify and hold Landlord harmless from any loss of or damage to Tenant
property, completed work, fixtures, equipment, materials or merchandise, and
from liability for death of, or injury to, any person, caused by the willful
misconduct or negligence of Tenant or its agents.

     7. NOTIFICATION OF DELAYS. Not less than once each calendar month from the
date of this Work Letter through the Term Commencement Date, Landlord shall
deliver to Tenant written notification of the number of days during the
immediately preceding calendar month Landlord's performance under this Work
Letter or the Lease was delayed as a result of Tenant Delays or delays arising
by reason of any Force Majeure as defined in Section 34 of the Lease (a "Force
Majeure Delay"), which written notification shall also include a description of
the nature of such Tenant Delay or Force Majeure Delay.

     8. MISCELLANEOUS.

     (a) CONSENTS. Whenever consent or approval of either party is required
under this Work Letter, that party shall not unreasonably withhold, condition or
delay such consent or approval, except as may be expressly set forth herein to
the contrary.

     (b) MODIFICATION. No modification, waiver or amendment of this Work
Agreement or of any of its conditions or provisions shall be binding upon
Landlord or Tenant unless in writing signed by Landlord and Tenant.

     (c) COUNTERPARTS. This Work Letter may be executed in any number of
counterparts but all counterparts taken together shall constitute a single
document.

     (d) GOVERNING LAW. This Work Letter shall be governed by, construed and
enforced in accordance with the internal laws of the state in which the Premises
are located, without regard to choice of law principles of such State.

     (e) TIME OF THE ESSENCE. Time is of the essence of this Work Agreement and
of each and all provisions thereof.

     (f) DEFAULT. Notwithstanding anything set forth herein or in the Lease to
the contrary, Landlord shall not have any obligation to perform any work
hereunder or to fund any portion of the TI Fund during any period Tenant is in
Default under the Lease.

     (g) SEVERABILITY. If any term or provision of this Work Letter is declared
invalid or unenforceable, the remainder of this Work Letter shall not be
affected by such determination and shall continue to be valid and enforceable.

     (h) MERGER. All understandings and agreements, oral or written, heretofore
made between the parties hereto and relating to Landlord's Work are merged in
this Work Letter, which alone (but inclusive of provisions of the Lease
incorporated herein and the final approved constructions drawings and
specifications prepared pursuant hereto) fully and completely

<PAGE>

expresses the agreement between Landlord and Tenant with regard to the matters
set forth in this Work Letter.

     (i) ENTIRE AGREEMENT. This Work Letter is made as a part of and pursuant to
the Lease and, together with the Lease, constitutes the entire agreement of the
parties with respect to the subject matter hereof. This Work Letter is subject
to all of the terms and limitation set forth in the Lease, and neither party
shall have any rights or remedies under this Work Letter separate and apart from
their respective remedies pursuant to the Lease.

     IN WITNESS WHEREOF, Landlord and Tenant have executed this Work Letter to
be effective on the date first above written.

                                    TENANT:

                                    t.BREEDERS, INC.,
                                    a Delaware corporation

                                    By: Signature on File
                                        -------------------------------------
                                    Its: President
                                        -------------------------------------

                                    LANDLORD:

                                    ARE-ONE INNOVATION DRIVE, LLC,
                                    a Delaware limited liability company

                                    By:  AREE-Holdings, L.P., a Delaware limited
                                         partnership, its managing member

                                    By:  ARE-GP Holdings QRS Corp., a
                                         Delaware corporation, its general
                                         partner

                                    By: /s/ Lynne Anne Shapiro
                                        -------------------------------------
                                    Its: General Counsel
                                        -------------------------------------

<PAGE>

                            SCHEDULE A TO WORK LETTER

                              DEVELOPMENT SCHEDULE
<Table>
<Caption>
         EVENT                                                  DATE
                                                                2/24/00
         <S>                                                    <C>
         Execution of lease

         Naming of Tenant's Representatives                     completed

         Delivery of TI Construction Drawings                   completed

         Commence construction of Tenant Improvements           within 5 days after
                                                                Commencement Date

         Substantial Completion of Tenant Improvements          within 90 days after
                                                                Commencement Date
</Table>

<PAGE>

                            SCHEDULE B TO WORK LETTER

<PAGE>

                            Exhibit A to Work Letter

                                 tBreeders, Inc.

                        List of TI Construction Drawings

<Table>
<S>      <C>                         <C>                        <C>                        <C>
AO       Cover Sheet                 Archdesign, Inc.           #6 Issued for Permit       12-21-99

Dl       Demolition Floor Plan       Archdesign, Inc.           #6 Issued for Permit       12-21-99

Al       First Floor Plan            Archdesign, Inc.           #6 Issued for Permit       12-21-99

A2       Reflected Ceiling Plan      Archdesign, Inc.           #6 Issued for Permit       12-21-99

A3       Schedules                   Archdesign, Inc.           #6 Issued for Permit       12-21-99

FP1      Fire Protection Plan        Noremac Sprinkler          #1 Permit Drawings         12-20-99

P-1      First Floor Plan            NSMC                       #1 Issued for Permit       12-15-99

M1       First Floor HVAC Plan       Environmental Systems      #2 Permit Issue            12-20-99

M2       Plans & Schedules           Environmental Systems      #2 Permit Issue            12-20-99

El       First Floor Lighting        Shepard Engineering        #5 Design Development      12-06-99
</Table>

<PAGE>

                               EXHIBIT D TO LEASE

                       ACKNOWLEDGMENT OF COMMENCEMENT DATE

     This ACKNOWLEDGMENT OF COMMENCEMENT DATE is made this ____ day of
__________, between ARE-ONE INNOVATION DRIVE, LLC, a Delaware limited liability
company ("Landlord"), and t.BREEDERS, INC., a Delaware corporation ("TENANT"),
and is attached to and made a part of the Lease dated ___________, (the
"LEASE"), by and between Landlord and Tenant. Any initially capitalized terms
used but not defined herein shall have the meanings given them in the Lease.

     Landlord and Tenant hereby acknowledge and agree, for all purposes of the
Lease, that the Commencement Date of the Base Term of the Lease is
______________, and the termination date of the Base Term of the Lease shall be
midnight on ____________, ______

     IN WITNESS WHEREOF, Landlord and Tenant have executed this ACKNOWLEDGMENT
OF COMMENCEMENT DATE to be effective on the date first above written.

                                     TENANT:

                                     t. BREEDERS, INC.,
                                     a Delaware corporation

                                     By:
                                        ---------------------------------------
                                     Its:
                                         --------------------------------------

                                     LANDLORD:

                                     ARE-ONE INNOVATION DRIVE, LLC,
                                     a Delaware limited liability company

                                     By: AREE-Holdings, L.P.,
                                         a Delaware limited partnership,
                                         its managing member

                                     By: ARE-GP Holdings QRS Corp.,
                                         a Delaware corporation, its general
                                         partner

                                         By:
                                            --------------------
                                         Its:
                                             -------------------

<PAGE>

                               EXHIBIT E TO LEASE

                              RULES AND REGULATIONS

     1. The sidewalk, entries, and driveways of the Project shall not be
obstructed by Tenant, or its agents, or used by them for any purpose other than
ingress and egress to and from the Premises.

     2. Tenant shall not place any objects, including antennas, outdoor
furniture, etc., in the parking areas, landscaped areas or other areas outside
of its Premises, or on the roof of the Project.

     3. Except for seeing-eye dogs, no animals shall be allowed in the offices,
halls, or corridors in the Project.

     4. Tenant shall not disturb the occupants of the Project or adjoining
buildings by the use of any radio or musical instrument or by the making of loud
or improper noises.

     5. If Tenant desires telegraphic, telephonic or other electric connections
in the Premises, Landlord or its agent will direct the electrician as to where
and how the wires may be introduced; and, without such direction, no boring or
cutting of wires will be permitted. Any such installation or connection shall be
made at Tenant's expense.

     6. Tenant shall not install or operate any steam or gas engine or boiler,
or other mechanical apparatus in the Premises, except as specifically approved
in the Lease. The use of oil, gas or inflammable liquids for heating, lighting
or any other purpose is expressly prohibited. Explosives or other articles
deemed extra hazardous shall not be brought into the Project.

     7. Parking any type of recreational vehicles is specifically prohibited on
or about the Project. Except for the overnight parking of operative vehicles, no
vehicle of any type shall be stored in the parking areas at any time. In the
event that a vehicle is disabled, it shall be removed within 48 hours. There
shall be no "For Sale" or other advertising signs on or about any parked
vehicle. All vehicles shall be parked in the designated parking areas in
conformity with all signs and other markings. All parking will be open parking,
and no reserved parking, numbering or lettering of individual spaces will be
permitted except as specified by Landlord.

     8. Tenant shall maintain the Premises free from rodents, insects and other
pests.

     9. Landlord reserves the right to exclude or expel from the Project any
person who, in the judgment of Landlord, is intoxicated or under the influence
of liquor or drugs or who shall in any manner do any act in violation of the
Rules and Regulations of the Project.

     10. Tenant shall not cause any unnecessary labor by reason of Tenant's
carelessness or indifference in the preservation of good order and cleanliness.
Landlord shall not be responsible to Tenant for any loss of property on the
Premises, however occurring, or for any damage done to the effects of Tenant by
the janitors or any other employee or person.

<PAGE>

     11. Tenant shall give Landlord prompt notice of any defects in the water,
lawn sprinkler, sewage, gas pipes, electrical lights and fixtures, heating
apparatus, or any other service equipment affecting the Premises.

     12. Tenant shall not permit storage outside the Premises, including without
limitation, outside storage of trucks and other vehicles, or dumping of waste or
refuse or permit any harmful materials to be placed in any drainage system or
sanitary system in or about the Premises.

     13. All moveable trash receptacles provided by the trash disposal firm for
the Premises must be kept in the trash enclosure areas, if any, provided for
that purpose.

     14. No auction, public or private, will be permitted on the Premises or the
Project.

     15. No awnings shall be placed over the windows in the Premises except with
the prior written consent of Landlord.

     16. The Premises shall not be used for lodging, sleeping or cooking or for
any immoral or illegal purposes or for any purpose other than that specified in
the Lease. No gaming devices shall be operated in the Premises.

     17. Tenant shall ascertain from Landlord the maximum amount of electrical
current which can safely be used in the Premises, taking into account the
capacity of the electrical wiring in the Project and the Premises and the needs
of other tenants, and shall not use more than such safe capacity. Landlord's
consent to the installation of electric equipment shall not relieve Tenant from
the obligation not to use more electricity than such safe capacity.

     18. Tenant assumes full responsibility for protecting the Premises from
theft, robbery and pilferage.

     19. Tenant shall not install or operate on the Premises any machinery or
mechanical devices of a nature not directly related to Tenant's ordinary use of
the Premises and shall keep all such machinery free of vibration, noise and air
waves which may be transmitted beyond the Premises.

<PAGE>

                               EXHIBIT F TO LEASE

                           TENANT'S PERSONAL PROPERTY

                                   [ATTACHED]

<PAGE>

                                    Exhibit F

                       List of Tenant's Personal Property

All Office Desks, Chairs, File Cabinets, Bookcases
All demountable Office Partition Systems
All freestanding Shelving Units and Systems
All Office Equipment, Computers, Typewriters, Phones
All Cork Boards, Chalk Boards, Bulletin Boards
All Office Supplies
All Laboratory Supplies
All Benchtop and portable Laboratory Equipment
All Laboratory Refrigerators, Freezers, Incubators, Biological Safety Cabinets,
Centrifuges, Balances, Ovens, Ice
Makers, and other laboratory equipment not integrally attached to the building
or building systems.
All Autoclaves, Glassware Washers, Glassware Dryers
All freestanding, non-attached Storage Cabinets, File Cabinets, Shelving Units

<PAGE>

                               EXHIBIT G TO LEASE

                              ESTOPPEL CERTIFICATE

     THIS TENANT ESTOPPEL CERTIFICATE ("CERTIFICATE"), dated as of _______, is
executed by _________________ ("TENANT") in favor of [BUYER], a
________________________________ together with its nominees, designees and
assigns (collectively, "Buyer"), and in favor of _____________, together with
its nominees, designees and assigns (collectively, "LENDER").

                                    RECITALS

     A. Buyer and ___________ ("Landlord"), have entered into that certain
Purchase and Sale Agreement and Joint Escrow Instructions, dated as of
_________, 19_ (the "PURCHASE AGREEMENT"), whereby Buyer has agreed to purchase,
among other things, the improved real property located in the City of _________,
County of _________, State of _________ more particularly described on Exhibit A
attached to the Purchase Agreement (the "PROPERTY").

     B. Tenant and Landlord have entered into that certain Lease Agreement,
dated as of ___________ (together with all amendments, modifications,
supplements, guarantees and restatements thereof, the "LEASE"), for a portion of
the Property.

     C. Pursuant to the Lease, Tenant has agreed that upon the request of
Landlord, Tenant would execute and deliver an estoppel certificate certifying
the status of the Lease.

     D. In connection with the Purchase Agreement, Landlord has requested that
Tenant execute this Certificate with an understanding that Lender will rely on
the representations and agreements below in granting to Buyer a loan.

     NOW, THEREFORE, Tenant certifies, warrants, and represents to Buyer and
Lender as follows:

     1. LEASE. Attached hereto as EXHIBIT B is a true, correct and complete copy
of the Lease, including the following amendments, modifications,
supplements, guarantees and restatements thereof, which together represent all
of the amendments, modifications, supplements, guarantees and restatements
thereof:

--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
(If none, please state "None.")

     2. PREMISES. Pursuant to the Lease, Tenant leases those certain premises
(the "Premises") consisting of approximately _______________ rentable square
feet within the Property, as more particularly described in the Lease. In
addition, pursuant to the terms of the Lease, Tenant has the [non-exclusive]
right to use (_____ parking spaces/the parking area] located on the Property
during the term of the Lease. (Cross-out the preceding sentence or portions
thereof if inapplicable.]

<PAGE>

     3. FULL FORCE OF LEASE. The Lease has been duly authorized, executed and
delivered by Tenant, is in full force and effect, has not been terminated, and
constitutes a legally valid instrument, binding and enforceable against Tenant
in accordance with its terms, subject only to applicable limitations imposed by
laws relating to bankruptcy and creditor's rights.

     4. COMPLETE AGREEMENT. The Lease constitutes the complete agreement between
Landlord and Tenant for the Premises and the Property, and except as modified by
the Lease amendments noted above (if any), has not been modified, altered or
amended.

     5. ACCEPTANCE OF PREMISES. Tenant has accepted possession and is currently
occupying the Premises;

 6. LEASE TERM. The term of the Lease commenced on ____________ and ends on
_______________ subject to the following options to extend:____________________
_______________________________________________________________________________
_____________________________
(If none, please state "None.")

     7. PURCHASE RIGHTS. Tenant has no option, right of first refusal, right of
first offer, or other right to acquire or purchase all or any portion of the
Premises or all or any portion of, or interest in, the Property, except as
follows: ______________________________________________________________________
_______________________________________________________________________________
_____________________________
(If none, please state "None.")

     8. RIGHTS OF TENANT. Except as expressly stated in this Certificate,
Tenant:

          (a) has no right to renew or extend the term of the Lease;

          (b) has no option or other right to purchase all or any part of the
Premises or all or any part of the Property;

          (c) has no right, title, or interest in the Premises, other than as
Tenant under the Lease.

     9. RENT.

          (a) The obligation to pay rent under the Lease commenced on___________
The rent under the Lease is current, and Tenant is not in default in the
performance of any of its obligations under the Lease.

          (b) Tenant is currently paying base rent under the Lease in the amount
of $__________ per month. Tenant has not received and is not presently entitled
to any abatement, refunds, rebates, concessions or forgiveness of rent or other
charges, free rent, partial rent, or credits, offsets or reductions in rent,
except as follows: ___________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
__________________________. (If none, please state "None.")

<PAGE>

     (c) Tenant's estimated share of operating expenses, common area charges,
insurance, real estate taxes and administrative and overhead expenses is % and
is currently being paid at the rate of $__________ per month, payable to:
__________

     (d) There are no existing defenses or offsets against rent due or to become
due under the terms of the Lease, and, to the best of Tenant's knowledge, there
presently is no default or other wrongful act or omission by Landlord under the
Lease or otherwise in connection with Tenant's occupancy of the Premises, nor is
there a state of facts which with the passage of time or the giving of notice or
both could ripen into a default on the part of Tenant, or to the best knowledge
of Tenant, could ripen into a default on the part of Landlord under the Lease,
except as follows:___________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
________________________.(If none, please state "None.")

     10. SECURITY DEPOSIT. The amount of Tenant's security deposit held by
Landlord under the Lease is $___________________.

     11. PREPAID RENT. The amount of prepaid rent, separate from the security
deposit, is ___________ covering the period from _______ to _______.

     12. INSURANCE. All insurance, if any, required to be maintained by Tenant
under the Lease is presently in effect.

     13. PENDING ACTIONS. There is not pending or, to the knowledge of Tenant,
threatened against or contemplated by the Tenant, any petition in bankruptcy,
whether voluntary or otherwise, any assignment for the benefit of creditors, or
any petition seeking reorganization or arrangement under the federal bankruptcy
laws or those of any state.

     14. TENANT IMPROVEMENTS. As of the date of this Certificate, to the best of
Tenant's knowledge, Landlord has performed all obligations required of Landlord
pursuant to the Lease; no offsets, counterclaims, or defenses of Tenant under
the Lease exist against Landlord; and, to the best of Tenant's knowledge, no
events have occurred that, with the passage of time or the giving of notice,
would constitute a basis for offsets, counterclaims, or defenses against
Landlord, except as follows:__________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
________________________. (If none, please state "None.")

     15. ASSIGNMENTS BY LANDLORD. Tenant has received no notice of any
assignment, hypothecation or pledge of the Lease or rentals under the Lease by
Landlord. Tenant hereby consents to an assignment of the Lease and rents to be
executed by Landlord to Buyer or Lender in connection with the Loan and
acknowledges that said assignment does not violate the provisions of the Lease.
Tenant acknowledges that the interest of the Landlord under the Lease is to be
assigned to Buyer or Lender solely as security for the purposes specified in
said assignment and Buyer or Lender shall have no duty, liability or obligation
whatsoever under the Lease or any extension or renewal thereof, either by virtue
of said assignment or by any subsequent receipt or collection of rents
thereunder, unless Buyer or Lender shall specifically

<PAGE>

undertake such liability in writing. Tenant agrees that upon receipt of a
written notice from Buyer or Lender of a default by Landlord under the Loan,
Tenant will thereafter pay rent to Buyer or Lender in accordance with the terms
of the Lease provided that Tenant will have the right to rely on such notice
without independent inquiry as to its accuracy.

     16. ASSIGNMENTS BY TENANT. Tenant has not sublet or assigned the Premises
or the Lease or any portion thereof to any sublessee or assignee. No one except
Tenant and its employees will occupy the Premises. The address for notices to be
 .sent to Tenant is as set forth in the Lease.

     17. ENVIRONMENTAL MATTERS. The operation and use of the Premises does not
involve the generation, treatment, storage, disposal or release into the
environment of any hazardous materials, regulated materials and/or solid waste,
except those used in the ordinary course of operating for the Permitted Use, as
defined in the Lease, or otherwise used in accordance with all applicable laws.

     18. SUCCESSION OF INTEREST. Tenant agrees that, in the event Buyer or
Lender succeeds to the interest of Landlord under the Lease:

               (a) Buyer or Lender shall not be liable for any act or omission
          of any prior landlord (including Landlord);

               (b) Buyer or Lender shall not be liable for the return of any
          security deposit;

               (c) Buyer or Lender shall not be bound by any rent or additional
          rent which Tenant might have prepaid under the Lease for more than the
          current month;

               (d) Buyer or Lender shall not be bound by any amendments or
          modifications of the Lease after the date hereof made without prior
          consent of Buyer or Lender;

               (e) Buyer or Lender shall not be subject to any offsets or
          defenses which Tenant might have against any prior landlord (including
          Landlord); or

               (f) Buyer or Lender shall not be liable under the Lease to Tenant
          for the performance of Landlord's obligations under the Lease beyond
          Buyer or Lender's interest in the Property.

     19. NOTICE OF DEFAULT. Tenant agrees to give Buyer and Lender a copy of any
notice of default under the Lease served upon Landlord at the same time as such
notice is given to Landlord. Tenant further agrees that if Landlord shall fail
to cure such default within the applicable grace period, if any, provided in the
Lease, then Buyer or Lender shall have an additional 60 days within which to
cure such default, or if such default cannot be cured within such 60-day period,
such 60-day period shall be extended so long as Buyer or Lender has commenced
and is diligently pursuing the remedies necessary to cure such default
(including, but

<PAGE>

not limited to, commencement of foreclosure proceedings, if necessary to effect
such cure, in which event the Lease shall not be terminated while such remedies
are being pursued.

     Tenant makes this Certificate with the knowledge that it will be relied
upon by Buyer and Lender in agreeing to purchase the Property.

     Tenant has executed this Certificate as of the date first written above by
the person named below, who is duly authorized to do so.

     TENANT:
                                         ---------------------------------------
                                         a
                                          -------------------------------------

                                         By:
                                             ----------------------------------
                                             Name:
                                                  -----------------------
                                             Its:
                                                 ---------------------------

<PAGE>

                        EXHIBIT A TO ESTOPPEL CERTIFICATE

                                LEGAL DESCRIPTION

<PAGE>

                        EXHIBIT B TO ESTOPPEL CERTIFICATE

                                  COPY OF LEASE

<PAGE>

                               EXHIBIT H TO LEASE

                       SUBORDINATION, NON-DISTURBANCE AND
                              ATTORNMENT AGREEMENT

     THIS SUBORDINATION, NON-DISTURBANCE AND ATTORNMENT AGREEMENT is made and
entered into as of _________, ___, _____ ("Agreement"), by and between
________________ a ________________ together with its nominees, designees and
assigns (collectively, "Landlord"), ________________________, a _______________
("Tenant"), and __________________, a _____________("Mortgagee").

     WHEREAS, Mortgagee is making a loan to Landlord and others evidenced by a
certain promissory note ("Note"), and secured by, among other things, a deed of
trust/mortgage to be recorded prior hereto in the public records of the City of
_________, County of __________, State of _______ ("Mortgage") constituting a
lien upon the real property described in Exhibit A hereto (the "Real Property");
and

     WHEREAS, ____________________________ and Tenant have entered into a Lease
Agreement dated as of ________________, _____ ("Lease"), for certain leased
premises encompassing _____________________________________ located in
_____________, containing approximately _________________________ net square
feet (hereinafter collectively referred to as "Premises"); and

     WHEREAS, subject to the provisions hereof, the Lease is subordinate to the
Mortgage and to the right, title, and interests of Mortgagee thereto and
thereunder; and

     WHEREAS, Mortgagee wishes to obtain from Tenant certain assurances that
Tenant will attorn to Mortgagee in the event of a foreclosure by Mortgagee or
the exercise of other rights under the Mortgage; and

     WHEREAS, Tenant wishes to obtain from Mortgagee certain assurances that
Tenant's possession of the Premises will not, subject to the terms and
conditions of this Agreement, be disturbed by reason of a foreclosure of the
lien of the Mortgage on the Real Property; and

     WHEREAS, Tenant and Mortgagee are both willing to provide such assurances
to each other upon and subject to the terms and conditions of this Agreement.

     NOW, THEREFORE, in consideration of the above, the mutual promises
hereinafter set forth, and other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, the parties hereto mutually
agree as follows:

<PAGE>

     1. AFFIRMATION. Tenant hereby agrees that the Lease now is and shall be
subject and subordinate in all respects to the Mortgage and to all renewals,
modifications and extensions thereof until such time that the Mortgage is
released, satisfied or otherwise discharged, subject to the terms and conditions
of this Agreement. Landlord and Tenant hereby affirm that the Lease is in full
force and effect and that the Lease has not been modified or amended. Mortgagee
hereby confirms that it is the holder of the Note and the beneficiary of the
Mortgage and has full power and authority to enter into this Agreement.

     2. ATTORNMENT AND NON-DISTURBANCE.

     (a) So long as Tenant is not in default under the Lease (beyond Tenant's
receipt of notice from Landlord and any grace period granted Tenant under the
Lease to cure such default) as would entitle the Landlord to terminate the Lease
or would cause without any further action of the Landlord, the termination of
the Lease or would entitle the Landlord to dispossess Tenant thereunder then
Mortgagee agrees with Tenant that in the event the interest of Landlord shall be
acquired by Mortgagee or in the event Mortgagee comes into possession of or
acquires title to the Real Property by reason of foreclosure or foreclosure sale
or the enforcement of the Mortgage or the Note or other obligation secured
thereby or by a conveyance in lieu thereof, or as a result of any other means
then:

          (i) Subject to the provisions of this Agreement, Tenant's occupancy
     and possession of the Premises and Tenant's rights and privileges under the
     Lease or any extensions, modifications or renewals thereof or substitutions
     therefor (in accordance with the Lease and the Mortgage) shall not be
     disturbed, diminished or interfered with by Mortgagee during the term of
     the Lease (or any extensions or renewals thereof provided for in the
     Lease);

          (ii) Mortgagee will not join Tenant as a party defendant in any action
     or proceeding for the purpose of terminating Tenant's interest and estate
     under the Lease because of any default under the Mortgage; and

          (iii) The Lease shall continue in full force and effect and shall not
     be terminated except in accordance with the terms of the Lease.

          (b) Tenant shall be bound to Mortgagee under all of the terms,
     covenants and conditions of the Lease for the balance of the term thereof
     remaining (and any extensions or renewals thereof which may be effected in
     accordance with any option contained in the Lease) with the same force and
     effect as if Mortgagee were the landlord under the Lease, and Tenant does
     hereby agree to attorn to Mortgagee as its landlord, said attornment to be
     effective and self-operative without the execution of any other instruments
     on the part of either party hereto immediately upon Mortgagee's succeeding
     to the interest of Landlord under the Lease. Upon request of Lender, Tenant
     shall execute and deliver to Lender an agreement reaffirming such
     attornment.

          (c) If the Mortgage is foreclosed and any party ("Purchaser") other
     than Mortgagee purchases the Premises and succeeds to the interest of
     Landlord under the Lease, Tenant shall likewise be bound to Purchaser and
     Tenant hereby covenants and

<PAGE>

     agrees to attorn to Purchaser in accordance with all of the provisions of
     this Agreement; provided, however, that Purchaser shall have transmitted to
     Tenant a written document in recordable form, whereby Purchaser agrees to
     recognize Tenant as its lessee under the Lease and agrees to be directly
     bound to Tenant for the performance and observance of all the terms and
     conditions of the Lease required to be performed or observed by Landlord
     thereunder, subject to and in accordance with the terms of this Agreement.

          (d) Mortgagee agrees that if Mortgagee shall succeed to the interest
     of Landlord under the Lease as above provided, Mortgagee shall be bound to
     Tenant under all of the terms, covenants, and conditions of the Lease, and
     Tenant shall, from and after Mortgagee's succession to the interest of
     Landlord under the Lease, have the same remedies against Mortgagee that
     Tenant might have had under the Lease against Landlord if Mortgagee had not
     succeeded to the interest of Landlord; provided, however, that Mortgagee
     (and Purchaser, as the case may be) shall not be:

               (i) liable for any act or omission of any prior lessor (including
     Landlord) occurring prior to the date that Mortgagee or Purchaser acquired
     title to the Premises;

               (ii) subject to any offsets, counterclaims or defenses which
     Tenant might have against any prior lessor (including Landlord);

               (iii) bound by any previous payment of rent or additional rent
     for a period greater than 1 month unless such prepayment shall have been
     consented to in writing by Mortgagee;

               (iv) bound by any amendment or modification of the Lease made
     prior to the date Mortgagee or Purchaser succeeds to the interest of
     Landlord without Mortgagee's written consent;

               (v) liable to Tenant for any toss of business or any other
     indirect or consequential damages from whatever cause; provided, however,
     no inference shall be drawn from this clause (v) that Tenant would
     otherwise be entitled (or not entitled) to recover for loss of business or
     any other indirect or consequential damages; or

               (vi) liable for the return of any security deposit unless such
     deposit has been paid over to the Mortgagee.

     The foregoing shall not be construed to modify or limit any right Tenant
may have at law or in equity against Landlord or any other prior owner of the
Real Property.

<PAGE>

     3. NOTICES. All notices required or permitted to be given pursuant to this
Agreement shall be in writing and shall be sent postage prepaid, by certified
mail, return receipt requested or other nationally utilized overnight delivery
service. All notices shall be deemed delivered when received or refused.
Rejection or other refusal to accept or inability to deliver because of changed
address of which no notice has been given shall constitute receipt of the
notice, demand or request sent. Any such notice if given to Tenant shall be
addressed as follows:

                   ---------------------------------------------
                   ---------------------------------------------
                   ---------------------------------------------
                   ---------------------------------------------
                   ---------------------------------------------

     if given to Landlord shall be addressed as follows:

     c/o Alexandria Real Estate Equities, Inc.
     135 N. Los Robles Avenue
     Suite 250
     Pasadena, California 91101
     Attention: General Counsel

     if given to Mortgagee shall be addressed as follows:

                   ---------------------------------------------
                   ---------------------------------------------
                   ---------------------------------------------
                   ---------------------------------------------
                   ---------------------------------------------

     4. SUCCESSORS AND ASSIGNS. This Agreement shall be binding upon and inure
to the benefit of the parties hereto and their respective successors and
assigns. The words "foreclosure" and "foreclosure sale" as used herein shall be
deemed to also include the acquisition of Landlord's estate in the Real Property
by voluntary deed, assignment or other conveyance or transfer in lieu of
foreclosure.

     5. MODIFICATIONS TO LEASE. Tenant shall not modify or amend the Lease or
terminate the same without Mortgagee's prior written consent. If Mortgagee fails
to provide Tenant with a written approval of the proposed modification,
amendment or termination within 10 business days after notice to Mortgagee of
such proposal, then Mortgagee shall be deemed to have rejected such proposal.

     6. ADDITIONAL AGREEMENTS. Tenant agrees that:

     (a) it shall give Mortgagee copies of all notices of default and requests
for approval or consent by Landlord that Tenant gives to Landlord pursuant to
the Lease in the same manner as they are given to Landlord and no such notice or
other communication shall be deemed to be effective until a copy is given to
Mortgagee;

<PAGE>

     (b) whenever any consent or approval by Landlord is required to be obtained
by Tenant or is requested by Tenant such consent or approval shall not be
effective until it is also confirmed by or obtained from Mortgagee, provided
that Mortgagee shall respond within 30 days after Mortgagee's receipt of
Tenant's request and failure of Mortgagee to respond in such time period shall
be deemed to be a denial of such consent or approval;

     (c) in all provisions of the Lease where Landlord is indemnified, the
reference to Landlord as an indemnitee shall be deemed to include Mortgagee and
any Purchaser and such agreement of indemnification shall survive the repayment
of the loan secured by the Mortgage and, to the extent provided in the Lease,
the expiration or termination of the Lease;

     (d) Tenant shall name Mortgagee and any Purchaser as additional insureds
and loss payees, as applicable and appropriate, on all insurance policies
required by the Lease;

     (e) this Agreement satisfies any condition or requirement in the Lease
relating to the granting of a non-disturbance agreement by Mortgagee, and if
there are inconsistencies between the terms and provisions of this Agreement and
the terms and provisions of the Lease dealing with non-disturbance by Mortgagee,
the terms and provisions hereof shall be controlling; and

     (f) Mortgagee shall have no liability under the Lease until Mortgagee
succeeds to the rights of the Landlord under the Lease, and then only during
such period as Mortgagee is the landlord. At all times during which Mortgagee is
liable under the Lease, Mortgagee's liability shall be limited to Mortgagee's
interest in the Real Property.

     7. MORTGAGEE CURE RIGHTS. If Landlord shall have failed to cure any default
within the time period provided for in the Lease (including any applicable
notice and grace periods) and Tenant exercises any right to terminate the Lease,
Mortgagee, shall have an additional 30 days within which to cure to cure such
default, or if such default cannot by the exercise of reasonable efforts by
Mortgagee be cured within such period, then such additional time as may be
reasonable necessary to effect such a cure (including, if necessary, sufficient
time to complete foreclosure proceedings) provided that Mortgagee shall commence
and thereafter diligently pursue remedies to cure such default. The Lease shall
not be terminated (i) while such remedies are being diligently pursued or (ii)
based upon a default which is personal to Landlord and therefore not susceptible
to cure by Mortgagee or which requires possession of the Premises to cure.
Mortgagee shall in no event be obligated to cure any such default by Landlord
unless it forecloses. Nothing in this Section 7 shall affect any of Tenant's
termination rights under the Lease due to casualty or condemnation.

     8. DIRECTION TO PAY. Landlord hereby directs Tenant and Tenant agrees to
make all payments of amounts owed by Tenant under the Lease directly to
Mortgagee from and after receipt by Tenant of written notice from Mortgagee
directing Tenant to make such payments to Mortgagee. Tenant shall have the right
to rely on any such notice from Mortgagee and Mortgagee hereby indemnifies and
agrees to defend Tenant against any action by Landlord arising from Tenant's
reliance on such notice. (As between Landlord and Mortgagee, the foregoing
provision shall not be construed to modify any rights of Landlord under or any
provisions of the Mortgage or any other instrument securing the Note).

<PAGE>

     9. CONDITIONAL ASSIGNMENT. With reference to any assignment by Landlord of
Landlord's interest in the Lease, or the rents payable thereunder, conditional
in nature or otherwise, which assignment is made to Mortgagee, Tenant agrees
that the execution thereof by Landlord, and the acceptance thereof by Mortgagee
shall never be treated as an assumption by Mortgagee of any of the obligations
of Landlord under the Lease unless and until Mortgagee shall have succeeded to
the interest of Landlord. The foregoing sentence shall not affect any of
Tenant's rights against Landlord under the Lease.

                           [SIGNATURES ON NEXT PAGE]
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
properly executed by their duly authorized representatives as of the date first
above written.

TENANT:
                                           ---------------------------------
                                           a--------------------------------

                                           By:
                                              ------------------------------
                                           Its:
                                               -----------------------------

LANDLORD:                                  [INSERT APPROPRIATE SIGNATURE BLOCK]

MORTGAGEE:
                                           ---------------------------------
                                           a--------------------------------

                                           By:
                                              ------------------------------
                                             Name:
                                                  --------------------------
                                             Its:
                                                 ---------------------------

<PAGE>

                      EXHIBIT A TO SUBORDINATION AGREEMENT

                                Legal Description

<PAGE>

                                   EXHIBIT A

Floor plan of one Innovation Drive, 1st Floor Premises of
t.Breeders, 12,254 SF

<PAGE>

                                   WORK LETTER

                                   SCHEDULE B

Floor plan of one Innovation Dr., 1st Floor, Premises of t.Breeders, Inc.
<PAGE>

                            FIRST AMENDMENT TO LEASE

     This First Amendment to Lease ("First Amendment") is made as of May 31,
2001, by and between ARE-ONE INNOVATION DRIVE, LLC, a Delaware limited liability
company ("Landlord"), and VIACELL, INC., a Delaware corporation ("TENANT")

                                    RECITALS

     A. Landlord is the landlord and Tenant is the tenant under a Lease dated as
of February 24, 2000 (the "Lease"), between Landlord and Tenant's predecessor by
name change t.Breeders, Inc., under which Tenant leases approximately 12,254
rentable square feet of space in the building commonly known as One Innovation
Drive, Worcester, Massachusetts. Capitalized terms used herein without
definition shall have the meanings defined for such terms in the Lease.

     B. Landlord and Tenant desire to amend the Lease to expand the Premises
[illegible] demised thereunder to consist of current [illegible] space and
adding approximately 4,947 rentable square feet to the Premises demised under
the Lease in three locations as follows:

          (a) approximately 1,578 rentable square feet located on the 4th floor
of the Building, as depicted on EXHIBIT A1 attached hereto and incorporated
herein by this reference ("EXPANSION SPACE ONE");

          (b) approximately 2,263 rentable square feet located on the 4th floor
of the Building, as depicted on EXHIBIT A2 attached hereto and incorporated
herein by this reference ("EXPANSION SPACE TWO"); and

          (c) approximately 1,106 rentable square feet located on the 1st floor
of the Building, as depicted on EXHIBIT A3 attached hereto and incorporated
herein by this reference ("Expansion Space Three");

(collectively, the "EXPANSION SPACE").

     C. Landlord and Tenant desire to amend the Lease to, among other things,
add the Expansion Space to the Premises demised under the Lease and to provide
for the improvement of such space.

                                    AGREEMENT

     Now, therefore, the parties hereto agree that the Lease is hereby amended
as follows:

1. THE PREMISES. Effective as June 1, 2001, the Premises demised under the Lease
shall include Expansion Space One (consisting for all purposes of the Lease of
1,578 rentable square feet). The monthly Base Rent payable for the month of June
2001 shall be increased by $3,090.25 to $21,726.55 and Tenant's Share of
Operating Expenses during such month shall be 12.01%. Effective as July 1, 2001,
the Premises demised under the Lease shall include Expansion Space Two
(consisting for all purposes of the Lease of 2,263 rentable square feet) and
Expansion Space Three (consisting for all purposes of the Lease of 1,106
rentable square feet). From and after July 1, 2001 the monthly Base Rent payable
under the Lease shall be increased by $6,597.63 per

<PAGE>

month to $28,324.18 per month and Tenant's Share of Operating Expenses shall be
14.93%. Such Base Rent shall thereafter be subject to adjustment when and as
described in Section 4(b) of the Lease.

2. TERM: ACCEPTANCE OF PREMISES. The term of the lease of the Expansion Space
(the "TERM") shall commence as described in Section 1 above, shall be year to
year and shall be automatically renewed unless either Landlord or Tenant gives
notice on or before December 31 of any year of its election not to renew, in
which event the lease of the Expansion Space shall terminated on April 30 of the
following year (approximately 4 months later); provided, however that in all
events the lease of the Expansion Space shall terminate when the Term of the
Lease terminated. Tenant shall accept the Expansion Space in its condition as of
the date of delivery of such Expansion Space to Tenant, subject to all
applicable Legal Requirements. Upon such delivery, Landlord shall have no
obligation for any defects in the Expansion Space. Tenant's taking possession of
each increment of the Expansion Space shall be conclusive evidence that Tenant
accepts such portion of the Expansion Space and that such portion of the
Expansion Space was in good condition at the time possession was taken.

3. SECURITY DEPOSIT. Upon delivery to Landlord of a copy of this First Amendment
executed by Tenant, Tenant shall deliver to Landlord a cash deposit (3 months
rent) acceptable to Landlord (the "SECURITY DEPOSIT") in the amount of
$29,063.25 as security for Tenant's performance under the Lease.

4. ALTERATIONS. Any alteration of all or a portion of the Expansion Space shall
be subject to all of the provisions of Section 12 of the Lease.

5. MISCELLANEOUS.

     (a) This First Amendment is the entire agreement between the parties with
respect to the subject matter hereof and supersedes all prior and
contemporaneous oral and written agreements and discussions with respect to the
matters addresses herein. This Amendment may be amended only by an agreement in
writing, signed by the parties hereto.

     (b) This First Amendment is binding upon and shall insure to the benefit of
the parties hereto, their respective agents, employees, representatives,
officers, directors, divisions, subsidiaries, affiliates, assigns, heirs,
successors in interest and shareholders.

     (c) The First Amendment may be executed in any number of counterparts, each
of which shall be deemed an original, but all of which when taken together shall
constitute one and the same instrument. The signature page of any counterpart
may be detached therefrom without impairing the legal effect of the signature(s)
thereon provided such signature page is attached to any other counterpart
identical thereto except having additional signature pages executed by other
parties to this Amendment attached thereto.

     (d) Landlord and Tenant each represent and warrant that it has not dealt
with any broker, agent or other person (collectively "BROKER") in connection
with this transaction, and that no Broker brought about this transaction.
Landlord and Tenant each hereby agree to Indemnify and hold the other harmless
from and against any claims by any Broker

                                      - 2 -
<PAGE>

claiming a commission or other form of compensation by virtue of having dealt
with Tenant or Landlord, as applicable, with regard to this leasing transaction.

     (e) Except as amended and/or modified by this Amendment, the Lease is
hereby ratified and confirmed and all other terms of the Lease shall remain in
full force and effect, unaltered and unchanged by this Amendment. In the event
of any conflict between the provisions of this Amendment and the provisions of
the Lease, the provisions of this Amendment shall prevail. Whether or not
specifically amended by this Amendment, all of the terms and provisions of the
Lease are hereby amended to the extent necessary to give effect to the purpose
and intent of this Amendment

                           [signatures on next page]

<PAGE>
     IN WITNESS WHEREOF, this First Amendment to Lease has been duly executed
and delivered by Landlord and Tenant as of the date first above written.

                                        TENANT:

                                        VIACELL, INC.
                                        a Delaware corporation

                                        By: Signature on file
                                           ------------------------------------
                                        Its: CEO
                                            -----------------------------------

                                        LANDLORD:
                                        ARE-One Innovation Drive, LLC,
                                        a Delaware limited liability company

                                        By: ALEXANDRIA REAL ESTATE EQUITIES,
                                            L.P.,
                                            a Delaware limited partnership,
                                            managing member

                                        By: ARE-QRS CORP.,
                                            a Maryland corporation,
                                            general partner

                                            By: Michael C. Keley
                                               --------------------------------
                                            Its: Senior Vice President
                                                -------------------------------
                                                 Real Estate Legal Affairs

                                      - 3 -
<PAGE>

                                   EXHIBIT A-1

                      Depiction of the Expansion Space One

                                      - 4 -
<PAGE>

                                   EXHIBIT A-2

                      Depiction of the Expansion Space Two

                                      - 5 -
<PAGE>

                                   Exhibit A-3
                     Depiction of the Expansion Space Three

                                      - 6 -<PAGE>

                                                              Exhibit 10.19

                                    SUBLEASE

     This SUBLEASE (the "Sublease") is dated as of the 27th day of December,
2000 by and between AIDS ACTION COMMITTEE OF MASSACHUSETTS, INC., a
Massachusetts corporation ("SUBLANDLORD"), and VIACELL, INC., a Delaware
corporation ("SUBTENANT").

                                    RECITALS

     WHEREAS, pursuant to that certain Lease dated as of June 30, 1988 by and
between John Hancock Mutual Life Insurance Company ("PRIME LANDLORD"), as
landlord, and Sublandlord, as tenant, as amended by (i) that certain First
Amendment to Lease dated June 29, 1988; (ii) that certain Second Amendment to
Lease dated January 6, 1992; (iii) that certain Third Amendment to Lease dated
January 11, 1993; (iv) that certain Fourth Amendment to Lease dated June 9, 1994
and (v) that certain Fifth Amendment to Lease dated as of December 2, 1997 (as
amended, the "PRIME LEASE"), a copy of which Prime Lease is attached hereto as
EXHIBIT A, Sublandlord leased from Prime Landlord certain premises (the
"ORIGINAL PREMISES") located in the building commonly known as 131 Clarendon
Street, Boston, Massachusetts (the "BUILDING"), which Original Premises contain
approximately 28,160 rentable square feet of space, as more fully described in
the Prime Lease; and

     WHEREAS, Subtenant desires to sublease from Sublandlord a portion of the
Original Premises containing approximately 7,040 rentable square feet and
constituting the entire third (3rd) floor of the Building and more particularly
shown on the floor plan attached hereto as EXHIBIT B (the "SUBLEASED PREMISES"),
and Sublandlord is willing to sublease the Subleased Premises to Subtenant on
the provisions, covenants and conditions hereinafter set forth.

                                    AGREEMENT

     NOW, THEREFORE, in consideration of Ten Dollars ($10.00), the mutual
covenants made herein, and other consideration, the receipt and sufficiency of
which are hereby acknowledged and agreed, Sublandlord hereby subleases to
Subtenant and Subtenant hereby takes and hires from Sublandlord the Subleased
Premises, on the terms and conditions set forth below:

     I. DEFINED TERMS. All terms defined in the Prime Lease and used herein
shall, unless otherwise defined herein, have the meanings ascribed to such terms
in the Prime Lease.

     II. LEASE GRANT. Subject to the terms of this Sublease, Sublandlord leases
to Subtenant, and Subtenant leases from Sublandlord the Subleased Premises for
the Sublease Term (as defined herein), together with the right, in common with
others entitled thereto from time to time, to use the Appurtenant Exterior Areas
and common areas and facilities of the Building, including, but not limited to,
the loading dock, hallways, alleys, lobbies and passenger and freight elevators
necessary for access to the Subleased Premises and lavatories nearest to the
Subleased Premises. The term "APPURTENANT EXTERIOR AREAS" means the areas
appurtenant to the Building and intended for Subtenant's use, including, without
limitation, all driveways and walkways necessary for access to the Subleased
Premises.

<PAGE>

     III. TERM. The term of this Sublease (the "SUBLEASE TERM") shall commence
on the later of (i) December 15, 2000 and (ii) the date on which Subtenant
receives written consent from Prime Landlord to this Sublease (the "SUBLEASE
TERM COMMENCEMENT DATE"), and shall continue until August 31, 2003, unless
sooner terminated in accordance with the provisions of this Sublease.

     IV. DELIVERY; ALTERATIONS. The Subleased Premises shall be delivered to
Subtenant on the Sublease Term Commencement Date, broom-clean and free of all
occupants but otherwise "as-is, where-is and with all faults", without
representation or warranty, express or implied, and Subtenant hereby waives,
disclaims and renounces any representation or warranty. In accordance with
Section 13 of the Prime Lease, Subtenant may make any non-structural alterations
("Alterations") to the Subleased Premises subject to the prior written consent
of both Sublandlord and Prime Landlord. Subject to obtaining such consent,
Subtenant intends to make, at its sole expense, initial Alterations to the
Subleased Premises which shall include, without limitation, the removal or
relocation of internal, non-structural walls, painting and carpeting the
interior of the Subleased Premises, rewiring the Subleased Premises for computer
and telephone use, and installing office cubes. Upon Subtenant's delivery to
Sublandlord of plans and specifications for such initial Alterations,
Sublandlord shall review and approve or disapprove the same in a timely fashion.
Provided that Sublandlord has consented to any such Alterations, Sublandlord
shall use reasonable efforts and cooperate with Subtenant to obtain Prime
Landlord's consent thereto.

     V. FIXED RENT. From and after the date that is two (2) months after the
Sublease Term Commencement Date (the "SUBLEASE RENT COMMENCEMENT DATE"),
Subtenant shall pay to Sublandlord, in advance, monthly installments, without
withholding, offset or reduction, Fixed Rent at the rate of $38.00 per rentable
square foot per annum (i.e., $22,293.33 per month). Fixed Rent for any partial
calendar months at the beginning or end of the Sublease Term shall be prorated
on a daily basis. Subtenant acknowledges that Sublandlord's payments of Fixed
Rent for the Original Premises are paid to Prime Landlord on the first day of
each calendar month during the Term and Subtenant therefore covenants, and
agrees that its payments of Fixed Rent hereunder shall be paid to Sublandlord at
least two (2) business days prior to the first of each calendar month, except
for the initial payment of Fixed Rent made on the Sublease Rent Commencement
Date.

     VI. ADDITIONAL RENT. Subtenant acknowledges that pursuant to Sections 6.1
and 6.4 of the Prime Lease, Sublandlord is obligated to pay to Prime Landlord
additional rent on account of operating costs and real estate taxes for the
Building, as more particularly described in such Sections. Subtenant shall pay
to Sublandlord with its monthly payment of Fixed Rent Subtenant's proportionate
share of the amount by which (x) Sublandlord's additional rent obligations under
the Prime Lease pursuant to Sections 6.1 and 6.4 thereof exceed (y)
Sublandlord's additional rent obligations under said Sections 6.1 and 6.4 for
calendar year 2001 with respect to operating expenses and fiscal year 2001 with
respect to real estate taxes, such proportionate share being 25.0% (the number
of rentable square feet in the Subleased Premises expressed as a percentage of
the number of rentable square feet in the Original Premises, referred to
hereinafter as "SUBTENANT'S PROPORTIONATE SHARE"). Sublandlord shall deliver to
Subtenant promptly after receipt thereof any statements of operating costs or
real estate taxes delivered to Sublandlord by Prime Landlord. Promptly after
Sublandlord and Prime Landlord have made the

                                      - 2 -
<PAGE>

appropriate adjustments between themselves on account of such actual operating
expenses and real estate taxes in accordance with Sections 6.2 and 6.9 of the
Prime Lease, Sublandlord and Subtenant similarly shall make adjustments to
Subtenant's payments of Subtenant's Proportionate Share of such additional rent.
The parties' obligations hereunder to make such adjustments shall survive the
expiration or early termination of this Sublease. Additional rent payable
hereunder for any partial calendar month at the beginning or end of the Sublease
Term shall be pro-rated on a daily basis.

     VII. USE. The Subleased Premises shall be used for general office uses for
administrative purposes and for uses ancillary thereto but for no other uses.
Subtenant acknowledges that, pursuant to Section 8 of the Prime Lease, the
Subleased Premises shall not be used as medical offices and/or medical clinics,
a school, or other classroom facility.

     VIII. PRIME LEASE. Subtenant agrees that it will do nothing in, on or about
the Subleased Premises which would result in the breach by Sublandlord of its
undertakings and obligations under the Prime Lease. Except for the following
provisions, this Sublease shall be subject to and on all of the terms and
conditions as are contained in the Prime Lease and the provisions of the Prime
Lease are hereby incorporated into this Sublease as if Sublandlord were the
landlord thereunder and Subtenant the tenant thereunder:

          A. The defined economic terms for "Fixed Rent," "Term," "Premises" and
the like are inapplicable;

          B. Section 5 of the Prime Lease (relating to Sublandlord's Security
Deposit) is inapplicable;

          C. Sections 6.1 and 6.4 of the Prime Lease (relating to additional
rent) are applicable, as modified by the provisions of Paragraph VI of this
Sublease;

          D. Section 14 of the Prime Lease (relating to assignment and
subletting) is inapplicable;

          E. Section 25 of the Prime Lease (relating to brokers) is
inapplicable; and

          F. Where appropriate, references to "Landlord" in the Prime Lease
shall be deemed to mean "Sublandlord" hereunder and references to "Tenant" in
the Prime Lease shall be deemed to mean "Subtenant" hereunder, it being
understood and agreed that Sublandlord will not be acting as, or assuming any of
the responsibilities of, Prime Landlord, and all references in the Prime Lease
to Landlord-provided services or Landlord insurance requirements, and any other
references which by theft nature relate to the owner or operator of the
Building, rather than to a tenant of the Building subleasing space to a
subtenant, shall continue to be references to Prime Landlord and not to
Sublandlord.

     IX. SUBTENANT'S COVENANTS. Subject to the provisions of Paragraph VIII
hereof, Subtenant covenants to Sublandlord to perform all of the covenants and
obligations to be performed by Sublandlord as Tenant under the Prime Lease as
the same relate to the Subleased Premises and to comply with this Sublease and
the applicable provisions of the Prime Lease, as

                                      - 3 -
<PAGE>

modified by this Sublease, in all respects. If Subtenant shall fail to make any
payment or perform any act required to be made or performed by Subtenant under
the Prime Lease pursuant to Subtenant's assumption of Sublandlord's obligations
thereunder as they relate to the Subleased Premises, and such default is not
cured by Subtenant by the first to occur of (i) one-half of the period specified
in the Prime Lease for curing such default, or (ii) five (5) days prior to the
expiration of such Prime Lease cure period, Sublandlord, without waiving or
releasing any obligation or default hereunder, may (but shall be under no
obligation to) make such payment or perform such act for the account and at the
expense of Subtenant, and may take any and all such actions as Sublandlord in
its sole discretion deems necessary or appropriate to accomplish such cure. If
Sublandlord shall reasonably incur any expense in remedying such default,
Sublandlord shall be entitled to recover such sums upon demand from Subtenant as
additional rent under this Sublease.

     X. SUBLANDLORD'S COVENANTS. Sublandlord covenants to Subtenant to perform
all of the terms and provisions required of it under the Prime Lease and to
promptly pay when due all rents due and accruing to Prime Landlord. Sublandlord
will use reasonable efforts to enforce on behalf of Subtenant Sublandlord's
rights under the Prime Lease. Nothing contained in this Sublease shall be
construed as a guarantee by Sublandlord of any of the obligations, covenants,
warranties, agreements or undertakings of Prime Landlord in the Prime Lease, nor
as an undertaking by Sublandlord to Subtenant on the same or similar terms as
are contained in the Prime Lease. Sublandlord shall not amend or modify (nor
agree to amend or modify) the Prime Lease in any way that would materially
increase Subtenant's obligations or materially diminish Subtenant's rights under
this Sublease, nor shall Sublandlord do, nor permit to be done, anything that
would cause the Prime Lease to be cancelled, terminated or forfeited.

     XI. INDEMNIFICATION. Subtenant shall indemnify Sublandlord and hold
Sublandlord harmless from and against any and all claims, demands suits,
judgments, liabilities, costs and expenses, including reasonable attorneys fees,
arising out of or in connection with Subtenant's use and possession of the
Subleased Premises, or arising out of the failure of Subtenant, its agents,
contractors or employees to perform any covenant, term or condition of this
Sublease or of the Prime Lease to be performed by Subtenant hereunder.
Sublandlord shall indemnify Subtenant and hold Subtenant harmless from and
against any and all claims, demands, suits, judgments, liabilities, costs and
expenses, including reasonable attorneys fees, arising out of the failure of
Sublandlord, its agents, contractors or employees to perform any covenant, term
or condition of this Sublease or of the Prime Lease to be performed by
Sublandlord hereunder.

     XII. ASSIGNMENT AND SUBLETTING. Subtenant shall not assign this Sublease in
whole or in part or sublet the Subleased Premises in whole or in part without
the prior written consent of Sublandlord, which consent shall not be
unreasonably withheld. No such sublease or assignment shall be effective without
the consent of Prime Landlord under the Prime Lease. If, as to any sublease or
assignment for which Sublandlord's consent is necessary, Subtenant receives rent
or other consideration in excess of the Fixed Rent and Additional Rent payable
under this Sublease, Subtenant shall pay to Sublandlord all of such excess,
after deducting Subtenant's reasonable legal and brokerage expenses and fit-up
expenses paid for by Subtenant at the time of such subleasing or assignment. If
Sublandlord and Prime Landlord consent to any such assignment or subletting,
Subtenant shall remain fully and primarily liable to Sublandlord, in all
respects, under the Sublease.

                                      - 4 -
<PAGE>

     Notwithstanding anything contained in this Sublease to the contrary, none
of the following, nor any assignments or transfers of this Sublease resulting
from the following, shall require Sublandlord's prior written consent or the
payment by Subtenant of any fees or charges of any kind:

        (a). a transfer of stock or other ownership interests in Subtenant;

        (b). the merger, consolidation or amalgamation of Subtenant with a third
party or the sale of all or substantially all of the stock or assets of
Subtenant so long as the surviving entity has a net worth greater than or equal
to that of Subtenant (i) as of the date of this Sublease or (ii) as of the day
immediately preceding such transaction, whichever is greater; or

        (c). a transfer to a parent, subsidiary or "affiliate" of Subtenant,
including, without limitation, ViaCord, Inc. An "affiliate" shall mean any
trust, corporation, partnership or limited liability company: (i) which owns or
"controls" the majority of the ownership interest of Subtenant, either directly
or indirectly through other entities; (ii) the majority of whose ownership
interests is owned or "controlled" by Subtenant; or (iii) which is under common
ownership with Subtenant, either directly or indirectly. As used herein, the
word "control" shall mean the right or power to direct or cause the direction of
the management and policies of the entity in question.

     XIII. SECURITY DEPOSIT. Upon execution hereof, Subtenant has delivered to
Sublandlord a letter of credit (the "LETTER OF CREDIT") in the amount of
$200,640.00 from Silicon Valley Bank, in the form attached hereto as EXHIBIT C,
as security for the performance of Subtenant's obligations under this Sublease.
Upon the occurrence of any default by Subtenant hereunder after expiration of
all grace or cure periods, or in the event Sublandlord receives notice that the
Letter of Credit will not be renewed in the amount and form required hereunder,
Subtenant agrees that Sublandlord may present the Letter of Credit for payment
and apply all or any part of such proceeds to any obligation of Subtenant
hereunder. If all or any portion of such proceeds of the Letter of Credit is
applied by Sublandlord against any of Subtenant's obligations hereunder,
Subtenant shall promptly restore the Letter of Credit to its original amount. In
the event that Sublandlord transfers the Letter of Credit to a third party,
Subtenant shall be responsible for all transfer fees incurred by Sublandlord in
connection with such transfer, and shall promptly pay such fees after receipt of
an invoice therefor from Sublandlord.

     At least thirty (30) days prior to the expiry of any Letter of Credit
provided to Sublandlord as Subtenant's Security Deposit hereunder, Subtenant
shall provide Sublandlord with a substitute Subtenant's Security Deposit in the
same amount (or, if permitted pursuant to this Paragraph XIII, any lesser
permitted amount) conforming to the provisions of this Paragraph XIII and in
substantially the same form as the Letter of Credit for this Sublease previously
approved by Sublandlord, but if effective during the final year of the Sublease
Term with an expiration date no earlier than thirty (30) days after the
expiration of the then extant Sublease Term.

     Notwithstanding anything in this Sublease to the contrary, provided that
Subtenant (i) at such time is not in default of its obligations under this
Sublease beyond any applicable grace or

                                      - 5 -
<PAGE>

cure period and (ii) has not been in such default beyond any applicable grace or
cure period, more than two times in the immediately preceding twelve (12)
months, the Letter of Credit shall be reduced by $66,880.00 (three months of
Fixed Rent) on February 20, 2002 and on February 20, 2003.

     XIV. BROKERS. Each of Sublandlord and Subtenant represents and warrants to
the other that it has not dealt with any broker in connection with this Sublease
other than Trammell Crow Company and Meredith & Grew (together, "Brokers"), and
each agrees to indemnify, defend and hold the other harmless from and against
any breach of said representation and warranty. Sublandlord shall be responsible
for the commission to be paid to Brokers pursuant to separate agreements.
Trammell Crow Company's commission shall be an amount equal to $3.00 per
rentable square foot in the Subleased Premises ($21,120.00).

     XV. UTILITIES. To the extent any such utilities are not separately metered
and billed directly to Subtenant, Subtenant shall be responsible for all
utilities (including light, plug and HVAC electricity) in the Subleased
Premises, to be paid by Subtenant to Sublandlord within ten (10) days after
billing therefor.

     XVI. SIGNAGE. Subject to Building standards, the provisions of the Prime
Lease and Sublandlord's approval, which approval shall not be unreasonably
withheld, Subtenant shall have the right to install, at Subtenant's sole
expense, signage in the lobby of the Building and at the entrance to the
Subleased Premises.

     XVII. SUBLANDLORD'S REPRESENTATIONS AND WARRANTIES. Sublandlord hereby
represents and warrants that: (1) Sublandlord is the tenant under the Prime
Lease and has the full right to enter into this Sublease (subject, however, to
obtaining Prime Landlord's consent); (ii) the Prime Lease is in full force and
effect; (iii) Sublandlord has not received from Prime Landlord any notice of any
default on the part of Sublandlord as tenant under the Prime Lease which has not
been cured, nor has Sublandlord given Prime Landlord notice of any default on
the part of Prime Landlord as landlord under the Prime Lease which has not been
cured; and (iv) Sublandlord has submitted to Subtenant a true and complete copy
of those portions of the Prime Lease that are pertinent to or affect Subtenant's
rights and obligations under the Sublease.

     If as a result of any default by Prime Landlord as landlord under the Prime
Lease, Sublandlord as tenant under the Prime Lease is entitled to any offset,
abatement or similar rights against Prime Landlord, to the extent that the same
is applicable to the Subleased Premises, Subtenant shall be entitled to
Subtenant's Proportionate Share of such offset, abatement or similar rights.

     XVIII. COVENANT OF QUIET ENJOYMENT. Subtenant, subject to the terms and
provisions of this Sublease, on payment of the Fixed Rent, additional rent and
other amounts payable hereunder, and observing, keeping, and performing all of
the terms and provisions of this Sublease on Subtenant's part to be observed,
kept, and performed, shall lawfully, peaceably, and quietly have, hold, occupy,
and enjoy the Subleased Premises during the Sublease Term without hindrance or
ejection by Sublandlord or by any person lawfully claiming under Sublandlord.

                                      - 6 -
<PAGE>

     XIX. RIGHT OF FIRST OFFER. If during the Sublease Term Sublandlord desires
to sublease all or a portion of the remaining Original Premises (the "Sublease
First Offer Space"), Sublandlord shall so notify Subtenant in writing, setting
forth the terms and conditions (the "Offer Terms") on which Sublandlord is
willing to so sublease the Sublease First Offer Space ("Sublandlord's Offer
Notice"). Subtenant may, by giving Sublandlord written notice within five (5)
business days after receipt of Sublandlord's Offer Notice, irrevocably elect to
sublease the Sublease First Offer Space on the Offer Terms. If Subtenant shall
so elect, Subtenant shall within ten (10) business days after such election
enter into a sublease or amendment to this Sublease incorporating the Offer
Terms and otherwise incorporating such terms and conditions as are mutually
acceptable to Sublandlord and Subtenant. If Subtenant shall fail to make such
election by within such 5-business-day period, then at Sublandlord's election,
Subtenant shall have no further rights with respect to the Sublease First Offer
Space, and Sublandlord shall thereafter be free to sublease any or all of the
Sublease First Offer Space to another party or parties, and on terms not
substantially more favorable to such party than the Offer Terms, provided that
the rental rate offered to any such third party shall not be less than 90% of
the rental rate offered to Subtenant.

     XX. MISCELLANEOUS.

          A. COUNTERPARTS. This instrument may be signed in counterpart
originals, which, taken together, shall constitute a single original instrument.

          B. NOTICES. Notices to Sublandlord or Subtenant required or permitted
hereunder shall be sent in the manner prescribed in the Prime Lease to the
Original Premises in the case of notices to Sublandlord and in the case of
notices to Subtenant to the following address:

                      551 Boylston Street, Suite 40
                      Boston, MA 02116
                      Attn:  Erin E. Quinn

                      with a copy to:

                      Palmer & Dodge LLP
                      One Beacon Street
                      Boston, MA 02108
                      Attn:  Thomas G. Schnorr, Esq.

          C. AMENDMENTS. This Sublease may not be changed or terminated orally
but only by an agreement in writing signed by both Sublandlord and Subtenant.

          D. ESTOPPEL CERTIFICATES. Sublandlord and Subtenant each agree to
furnish within twenty (20) days after written request therefor by the other, a
certificate stating (i) that this Sublease is in full force and effect and has
not been amended or modified (or describing such amendment or modification, if
any); (ii) the dates though which Fixed Rent and additional rent have been paid
hereunder; and (iii) that there are no defaults under this Sublease known to the
signer of the certificate (or specifying such defaults, if known).

                                      - 7 -
<PAGE>

          E. NO WAIVER. The failure of either party to insist on strict
performance of any covenant or condition hereof, or to exercise any option
contained herein, shall not be construed as a waiver of such covenant, condition
or option in any other instance.

          F. MEMORANDUM OF LEASE. Subtenant shall not record this Sublease or
any memorandum hereof.

          G. GOVERNING LAW. This Sublease has been negotiated, executed and
delivered in the Commonwealth of Massachusetts, and the parties agree that the
rights and obligations of the parties under this Sublease shall be governed and
construed in accordance with the laws of the Commonwealth of Massachusetts.

          H. SEVERABILITY. The invalidity of any of the provisions of this
Sublease will not impair or affect in any manner the validity, enforceability or
effect of the rest of this Sublease.

          I. ENTIRE AGREEMENT. All understandings and agreements, oral or
written, heretofore made between ,the parties hereto are merged in this
Sublease, which alone fully and completely expresses the agreement between
Sublandlord and Subtenant.

          J. RELATIONSHIP BETWEEN THE PARTIES. This Sublease does not create the
relationship of principal and agent, nor does it create any partnership, joint
venture, or any association or relationship between Sublandlord and Subtenant
other than as and to the extent specifically provided in this Sublease, the sole
relationship of Sublandlord and Subtenant being that of Sublandlord and
subtenant as provided in this Sublease.

          K. REMEDIES CUMULATIVE. Except as specifically provided herein, all
rights and remedies of the parties under this Sublease shall be cumulative and
none shall exclude any other rights and remedies allowed by law.

          L. CONDITION PRECEDENT. The effectiveness of this Sublease is
expressly subject to and conditional upon obtaining Prime Landlord's written
consent to this Sublease pursuant to Section 14 of the Prime Lease.

          M. AUTHORITY. Sublandlord warrants that Sublandlord is a duly existing
and valid Massachusetts corporation qualified to do business in Massachusetts,
that Sublandlord has duly executed and delivered this Sublease, that the
execution and delivery of; and the performance by Sublandlord of its obligations
under this Sublease are within the powers of Sublandlord and have been duly
authorized by all requisite corporate action, and that this Sublease is a valid
and binding obligation of Sublandlord in accordance with its terms. Subtenant
warrants that the Subtenant is a duly existing and valid Delaware corporation
qualified to do business in Massachusetts, that Subtenant has duly executed and
delivered this Sublease, that the execution and delivery of, and the performance
by Subtenant of its obligations under this Sublease are within the powers of
Subtenant and have been duly authorized by all requisite corporate action, and
that the Sublease is a valid and binding obligation of Subtenant in accordance
with its terms.

                  [remainder of page intentionally left blank]

                                      - 8 -
<PAGE>

     IN WITNESS WHEREOF, the parties have executed this Sublease as an
instrument under seal as of the date first written above.

                                 SUBLANDLORD:

                                 AIDS ACTION COMMITTEE OF MASSACHUSETTS, INC.,
                                 a Massachusetts corporation

                                 By: Signature on File
                                    ------------------------------------------
                                         Name:
                                         Title: Director

                                 SUBTENANT:

                                 VIACELL, INC., a Delaware corporation

                                 By: /s/ Marc Beer CEO
                                    ------------------------------------------
                                         Name:
                                         Title:

                                      - 9 -
<PAGE>

                                    EXHIBIT A

                                   PRIME LEASE

                                 [See Attached]

                                     - 10 -
<PAGE>

                                      LEASE

                               DATE: JUNE 30, 1988

1.   PARTIES          John Hancock Mutual Life Insurance Company, LESSOR, which
                      expression shall include its successors and assign where
                      the context so admits, does hereby lease to AIDS Action
                      Committee, Inc. LESSEE, which expression shall include its
                      successors and assigns where the context so admits, and
                      the LESSEE hereby leases the following described premises.

2.   PREMISES         ("Leased Premises"): That portion of 131 Clarendon Street,
                      Boston, MA. Consisting of the portion of the third floor
                      shown as Suites 2, 3, 4, 5 and 6, the entire fourth floor
                      and the entire fifth floor and containing approximately
                      19,250 retable square feet as shown on the attached
                      Exhibit A and commonly known and numbered as 131 Clarendon
                      Street, Boston, Massachusetts 02116, together with the
                      right to use in common, with others entitled thereto, the
                      alleys, loading docks, sidewalks, lobbies, hallways,
                      stairways, and passenger and freight elevators necessary
                      for access to said Leased Premises, and lavatories nearest
                      thereto.

3.   TERM             The term of the lease shall be for five (5) years
                      commencing on September 1, 1988 and ending on August 31,
                      1993.

4.   ANNUAL FIXED     The LESSEE shall pay to the LESSOR Annual Fixed Rent
                      (herein "Fixed Rate") at the rate of Three Hundred Eight
                      Thousand and 00/100 (308,000.00) dollars per year payable
                      in advance in monthly installments of Twenty Five Thousand
                      Six Hundred Sixty Six and 67/100 ($25,666.67) dollars due
                      and payable on the first day of each month. Effective
                      September 1, 1989. Fixed Rent will increase to Three
                      Hundred Twenty Seven Thousand Two Hundred Fifty and 00/100
                      ($327,250.00) dollars, per year payable in advance in
                      monthly installments of Twenty-Seven Thousand Two Hundred
                      Seventy and 88/100 ($27,270.88) dollars. Effective
                      September 1, 1990 Fixed Rent will increase to Three
                      Hundred Forty-Six Thousand Five Hundred and 00/100
                      ($346,500.00) dollars per year, payable in advance in
                      monthly installments of Twenty Eight Thousand Eight
                      Hundred Seventy Five and 00/100 (28,875.00) dollars.
                      Effective September 1, 1991 Fixed Rent will increase to
                      Three Hundred Sixty Five Thousand Seven Hundred Fifty and
                      ($365,750.00) dollars per year, payable in advance in
                      monthly installments of Thirty Thousand Four Hundred
                      Seventy Nine and 17/100 (30,479.17) dollars. Effective
                      September 1, 1992 Fixed Rent will increase to Three
                      Hundred Eighty Five Thousand

<PAGE>

                      and 00/100 ($385,000.00) dollars per year payable in
                      advance in monthly installments of Thirty Two Thousand
                      Eighty Three and 33/100 ($32,083.33) dollars. Payments are
                      to be made to Meredith & Crew, Incorporated, 160 Federal
                      Street, Boston, Massachusetts 02110-1701.

                      Upon the execution of this lease, the LESSEE shall pay to
                      the LESSOR the amount of Twenty Five Thousand Six Hundred
                      Sixty Six and 67/100 ($25,666.67), which shall be held as
                      a security for the LESSEE'S performance, as herein
                      provided and refunded to the LESSEE at the end of this
                      lease subject to the LESSEE'S satisfactory compliance with
                      the conditions hereof. No interest shall be payable on
                      said sum or any part thereof.

                      6.1 If in any year after calendar year 1988 LESSOR'S
                      operating expenses (as set forth on Exhibit B attached
                      hereto and incorporated herein by reference) for the
                      building of which the Leased Premises are a part (the
                      "Building") (exclusive of real estate taxes and financing
                      costs) exceed LESSOR'S operating expenses for the Building
                      (exclusive of real estate taxes and financing costs) for
                      calendar year 1988, LESSEE shall pay to LESSOR as
                      additional rent hereunder an amount equal to 31.5% of such
                      increase, LESSEE'S proportionate share is calculated as
                      follows: 19,250 rentable square feet in Leased Premises
                      divided by 61,110 rentable square feet in Building.

                      6.2 LESSEE shall pay additional rent for operating
                      expenses in monthly installment on the first day of each
                      calendar month in amounts reasonably estimated by LESSOR
                      for the then current period. LESSOR may from time to time
                      revise such estimates based on available information
                      relating to such operating express. Within a reasonable
                      time after the end of each calendar year, LESSOR shall
                      render to LESSEE a statement, according to generally
                      accepted accounting practices consistently applied,
                      certified by a financial officer of LESSOR's managing
                      agent on behalf of LESSOR, showing operating expenses for
                      such calendar year and the amount, if any, of additional
                      rent payable by LESSEE pursuant to Section 6.1. Upon
                      reasonable notice, LESSEE shall have access during
                      business hours to LESSOR's books and records supporting
                      such statement each year. LESSEE shall pay to LESSOR any
                      such amount of additional rent shown on such statement,
                      less any amounts previously paid by LESSEE on account
                      thereof, within fifteen (15) days after such statement is
                      rendered. In case, such statement shows an overpayment by
                      LESSEE, LESSOR shall apply such overpayment to rent next
                      coming due hereunder or, if no rent is due, LESSOR shall
                      include with such statement a refund of such overpayment.

                                      - 2 -
<PAGE>

                      6.3 If this lease shall commence or terminate in the
                      middle of a calendar year, LESSEE shall be liable for only
                      that portion of such increase in respect of such calendar
                      year represented by a fraction, the numerator of which is
                      the number of days of the term herein which fall within
                      the calendar year and the denominator of which is three
                      hundred sixty-five (365).

                      6.4 LESSEE shall also pay as additional rent hereunder
                      31.5% of the amount by which real estate taxes levied on
                      the building and the parcel of land on which the Building
                      is located (the "Property") for any fiscal tax year during
                      the term of this lease exceed the real estate taxes levied
                      against the Property during the Fiscal Tax Year 1988
                      (commencing July 1, 1987 and ending June 30, 1988).
                      LESSEE's proportionate share is calculated as follows:
                      19,250 rentable square feet in Leased Premises divided by
                      61,110 rentable square feet in Building.

                      6.5 The term "real estate taxes" shall mean all taxes and
                      special or betterment assessments of every kind and nature
                      assessed by any governmental authority on the Property
                      which LESSOR shall become obligated to pay because of or
                      in connection with the ownership, leasing and operation of
                      the same. There shall be excluded from real estate taxes
                      all income taxes, excess profit taxes, excise taxes,
                      franchise taxes, estate, succession, inheritance and
                      transfer taxes imposed on LESSOR as a result of its
                      ownership of the Property; provide, however, that if at
                      any time during the term of this lease the present system
                      of ad valorem taxation of real property there shall be
                      assessed on LESSOR a capital levy or other tax on the
                      gross rents received with respect to the Property, or
                      federal, state, county, municipal, or other local income,
                      franchise, excise or similar tax, assessment, levy or
                      charge (distinct from any now in effect) measured by or
                      based, in whole or in part, upon any such gross rents,
                      then any and all such taxes, assessments, levies or
                      charges to the extent so measured or based, shall be
                      deemed to be included within the term "real estate taxes"
                      but only to the extent that the same would be payable if
                      the Property were the only property of LESSOR.

                      6.6 The real estate taxes upon the Property for any fiscal
                      year commencing July 1, and terminating the following June
                      30 shall mean such amounts as shall be finally determined
                      to be the real estate taxes payable with respect to the
                      Property for said fiscal tax year, that is, the real
                      estate taxes assessed against the Property for said fiscal
                      tax year less any abatements, refunds or rebates made
                      thereof. For the purpose of determining payments due from
                      LESSEE to LESSOR in accordance with the provisions of this
                      subsection: (i) the real estate taxes upon the Property
                      for any

                                      - 3 -
<PAGE>

                      fiscal tax year shall be deemed to be the real estate
                      taxes assessed for said fiscal tax year until such time as
                      an abatement, refund or rebate shall be made thereof, and
                      (ii) if any abatement, refund or rebate shall be made for
                      any fiscal tax year, and appropriate adjustment shall be
                      made in the amount payable from or paid by LESSEE to
                      LESSOR on account of real estate taxes, less LESSOR's
                      reasonable fees and expenses in obtaining such abatement,
                      and LESSOR shall apply such overpayments to rent next
                      coming due hereunder or, if no rent is due, LESSOR shall
                      refund any such overpayment.

                      6.7 For the fiscal tax year during which the term of this
                      lease shall commence or terminate, LESSEE shall only be
                      liable for a fraction of its share, the numerator of said
                      fraction being the number of days of the term of this
                      lease which fall within the fiscal tax year and the
                      denominator of said fraction being the total number of
                      days of the fiscal tax year.

                      6.8 It is understood by the parties hereto that there are
                      presently two tax billing periods for each fiscal tax
                      year, namely the billing period from July 1 through
                      December 31 of each year and the billing period from
                      January 1 through June 30 of each year. If the billing
                      periods or fiscal tax year shall be changed by the
                      governmental authorities having jurisdiction over the
                      Property, an appropriate adjustment shall be made to carry
                      out the intent of the parties hereto.

                      6.9 LESSOR shall pay additional rent for real estate taxes
                      in monthly installments on the first day of each calendar
                      month in amounts reasonably estimated by LESSOR for the
                      then current period. Within a reasonable time after the
                      end of each fiscal year, LESSOR shall render a statement
                      to LESSEE showing the actual real estate taxes levied on
                      the Property for said fiscal tax year, and the amount, if
                      any, of additional rent payable by LESSEE pursuant to
                      Section 6.4 LESSEE shall pay to LESSOR any such amount of
                      additional rent shown on such statements, less any amounts
                      previously paid by LESSEE on account thereof, within
                      fifteen (15) days after such statement is rendered. In
                      case, such statement show an overpayment by LESSEE, LESSOR
                      shall apply such overpayment to rent next coming due
                      hereunder or, if no rent is due, LESSOR shall include with
                      such statement a refund of such overpayment.

7.   UTILITIES        The LESSEE shall pay, as they become due, all bills for
                      electricity and other utilities that are furnished to the
                      Leased Premises, and separately metered. The LESSOR shall
                      provide and LESSEE shall Pay for all LESSEE's replacement
                      light tubes, lamps, bulbs and

                                      - 4 -
<PAGE>

                      ballasts. LESSOR shall have no obligation to provide
                      utilities other than the utilities within the Leased
                      Premises as of the commencement date of this lease. In the
                      event LESSEE requires additional utilities, the
                      installation and maintenance thereof shall be the LESSEE's
                      sole obligation, provided that such installation shall be
                      subject to the written consent of the LESSOR, which shall
                      not be unreasonably withheld or delayed.

8.   USE OF LEASED
     PREMISES         The LESSEE shall use the Leased Premises only for the
                      purpose of administration, fund raising and development
                      offices for its programs from time to time and for other
                      general office purposes. It is understood that the
                      foregoing shall not include medical offices and/or medical
                      clinics, a school or other classroom facility. It is also
                      understood that, except for periods when LESSEE's rights
                      have been sublet or assigned (in each case with LESSOR's
                      consent as provided in this Lease), LESSEE shall,
                      throughout the Term, use the Leased Premises as LESSEE's
                      main corporate offices, LESSEE shall not, without LESSOR's
                      consent, move its main office elsewhere and continue to
                      use the Leased Premises for LESSEE's programs.

9.   COMPLIANCE
     WITH LAWS        The LESSEE acknowledges that no trade or occupation shall
                      be conducted in the Leased Premises or use made thereof
                      which will be unlawful, noisy or contrary to any law or
                      any municipal by-law or ordinance in force in the city of
                      town in which the Leased Premises are situated and LESSEE
                      shall comply with laws and ordinances applicable to its
                      use of the Leased Premises.

10.  FIRE INSURANCE   The LESSEE shall not permit any use of the Leased Premises
                      which will make voidable any insurance on the Property of
                      which the Leased Premises are a part, or on the contents
                      of said Property or which shall be contrary to any law or
                      regulation from time to time established by the New
                      England Fire Insurance Rating Association, or any similar
                      body succeeding to its powers. It is understood that the
                      uses permitted hereunder are not, at the date hereof,
                      contrary to such law or regulation and do not make
                      voidable any such insurance. The LESSEE shall on demand
                      reimburse the LESSOR, and all other tenants, all extra
                      insurance premiums caused by the LESSEE's use of the
                      Leased Premises.

11.  MAINTENANCE
     OF PREMISES      The LESSEE agrees to maintain the Leased Premises in the
                      same condition as they are at the commencement of the term
                      or as they may be put in during the term of this lease,
                      reasonable wear and tear, damage by fire and other
                      casualty only excepted, and

                                      - 5 -
<PAGE>
                      whenever necessary, to replace plate glass and other glass
                      therein. The LESSEE shall not permit the Leased Premises
                      to be overloaded, damaged, stripped, or defaced, nor
                      suffer any waste. In accordance with the Rules and
                      Regulations, LESSEE shall obtain written consent of LESSOR
                      before erecting any sign on the Leased Premises. Except
                      for LESSOR's obligations under section 13 of this Lease,
                      LESSEE accepts the Leased Premises its "As Is" condition
                      as of on the date hereof.

12.  SERVICES
     PROVIDED BY
     THE LESSOR       LESSOR covenants to furnish during the lease term, through
                      LESSOR's employees or independent contractors, the
                      following services:

                      (a) Reasonable heat and air conditioning (except to the
                      extent that the same are furnished through separately
                      metered utilities) to the Leased Premises during normal
                      business hours on regular business days of the heating and
                      air conditioning season of each year. Normal business
                      hours are considered to be Monday through Friday from 8:00
                      a.m. to 6:00 p.m. and Saturday from 8:00 a.m. to 1:00
                      p.m., legal holidays excepted. If LESSEE requires
                      additional heat outside of normal business hours, LESSOR
                      will provide such heat at LESSOR's costs, which LESSEE
                      will reimburse.

                      In the event LESSEE requires additional air conditioning
                      for business machines, meeting rooms or other special
                      purposes, or, because of occupancy or excess electrical
                      loads, requires any additional air conditioning equipment,
                      such additional air conditioning equipment will be
                      installed and maintained by LESSEE at LESSEE's sole cost
                      and expense, provided that such installation shall be
                      subject to the written consent of the LESSOR, which shall
                      not be unreasonably withheld or delayed.

                      (b) Maintenance of the heating, ventilating and air
                      conditioning equipment in serviceable condition damage by
                      fire and other casualty or eminent domain taking only
                      excepted, unless such maintenance is required because of
                      the LESSEE or those for whose conduct the LESSEE is
                      responsible.

                      (c) Operation of the water cooling towers for air
                      conditioning purposes during normal business hours on
                      regular business days of the air conditioning season of
                      each year and outside of normal business hours of LESSOR's
                      costs, which LESSEE will reimburse.

                      (d) Operatorless passenger elevator service at all times
                      and freight elevator service, subject to reasonable
                      scheduling by LESSOR.

                                      - 6 -
<PAGE>

                      (e) Window washing of all windows in the Leased Premises,
                      both inside and out, weather permitting, at reasonable
                      intervals to be determined by LESSOR.

                      (f) Cleaning (such cleaning service is limited to the
                      common areas in said Building) as is customary in similar
                      buildings in said city.

                      (g) Reasonable hot and cold water for lavatory and toilet
                      purposes.

                      (h) Reasonable lighting of common areas of said Building
                      at all times.

                      (i) Maintenance of the structure of the Building of which
                      the Leased Premises are a part in serviceable condition
                      damage by fire and other casualty and eminent domain
                      taking only excepted, unless such maintenance is required
                      because of the LESSEE or those for whose conduct the
                      LESSEE is legally responsible.

                      (j) Provision of dumpster at the Building to receive trash
                      from the Leased Premises and provision for emptying of
                      dumpster.

                      (k) Building security services, including reasonable
                      security systems or procedures to be in effect outside of
                      normal business hours.

                      (1) Such additional services on such terms and conditions
                      as may be mutually agreed upon by the LESSOR and LESSEE.

                   All service is subject to interruption due to any accident,
                   to the making repairs, alterations or improvements to labor
                   difficulties, to the unavailability of fuel, electricity,
                   service or supplies from the sources from which they are
                   reasonably obtainable or to any cause beyond the LESSOR's
                   control. LESSOR shall use its best efforts to remedy the
                   cause of any such interruption and, if such interruption
                   materially interferes with or prohibits LESSEE's use of the
                   Leased Premises and continues for more than seven days, rent
                   and additional rent shall abate be equitably abated until the
                   interruption in question in remedied.

13.  ALTERATIONS -
     ADDITIONS        The LESSEE shall not make structural alterations or
                      additions to the Leased Premises, but may make
                      non-structural alterations provided the LESSOR consents
                      thereto in writing, which consent shall not be
                      unreasonably withheld or delayed. All such allowed
                      alterations shall be at LESSEE's expense. LESSEE shall
                      procure at LESSEE's sole expense all necessary permits and
                      licenses

                                      - 7 -
<PAGE>

                      before undertaking any work on the Leased Premises. All
                      such work shall be done in a good and workmanlike manner
                      employing materials of good quality and so as to conform
                      with all applicable zoning, building, fire, health and
                      other codes, regulations, ordinances and laws. LESSEE will
                      deliver copies of all necessary permits and licenses to
                      LESSOR prior to the commencement of such work. LESSEE
                      shall not permit any mechanics' liens, or similar liens,
                      to remain upon the Leased Premises for labor and material
                      furnished to LESSEE or claimed to have been furnished to
                      LESSEE in connection with work of any character performed
                      or claimed to have been performed a the direction of
                      LESSEE and shall cause any such lien to be released of
                      record forthwith without cost to LESSOR. Any alterations
                      or improvements made by the LESSEE, shall become the
                      property of the LESSOR at the termination of occupancy as
                      provided herein.

                      Lessor shall, by the following dates, perform the
                      following work in the Leased Premises and the Building at
                      Lessor's cost:

                           (a) By September 1, 1989, install all new Building
                      windows in the Leased Premises.

                           (b) By September 1, 1989, renovate Building lobby and
                      passenger elevator cabs in accordance with plans
                      appropriate, in LESSOR's reasonable judgment, for the
                      renovation of an older office building.

14.                   LESSEE covenants and agrees not to assign mortgage,
                      pledge, encumber or otherwise transfer this lease or make
                      any sublease or permit the occupancy of the Leased
                      Premises or any part thereof by anyone other than LESSEE
                      without first obtaining on each occasion the prior consent
                      in writing of LESSOR which shall not be unreasonably
                      withhold. As additional rent, LESSEE shall reimburse
                      LESSOR promptly for reasonable legal expenses incurred by
                      LESSOR in connection with any request by LESSEE for
                      consent to assignment or subletting. No assignment or
                      subletting shall in any way impair the continuing primary
                      liability of LESSEE hereunder, and no consent to any
                      assignment or subletting in a particular instance shall be
                      deemed to be a waiver of the obligation to obtain LESSOR's
                      approval in the case of any other assignment or
                      subletting.

                      If for any assignment or sublease or occupancy by another,
                      LESSEE receives rent or other consideration, either
                      initially or over the term of the assignment, sublease or
                      occupancy, in excess of the rent called for hereunder, or
                      in case of sublease of part of the Leased Premises, in
                      excess of such rent fairly allocable to the part

                                      - 8 -
<PAGE>

                      so subleased (hereinafter referred to as "Excess Rents"),
                      after appropriate adjustments to assure that all other
                      payments called for hereunder are appropriately taken into
                      account, LESSEE shall pay to LESSOR, as Additional Rent,
                      50% of the Excess Rents, as and when received by LESSEE.

                      If during the Term of this Lease (I) LESSEE requests
                      LESSOR's consent to a proposed subletting of seventy-five
                      percent (75%) or more of the space in the Leased Premises
                      or LESSEE has already sublet a portion or portions of the
                      Leased Premises and requests LESSOR's consent to a
                      proposed subletting of additional space in the Leased
                      Premises, the amount which would, when added to the amount
                      of space already so subleased by LESSEE, exceed
                      seventy-five percent (75%) of the Leased Premises, then
                      LESSEE's request for LESSOR's consent shall constitute an
                      offer to LESSOR to release from this Lease that portion of
                      the Leased Premises proposed to be sublet, which offer
                      LESSOR may accept within 30 days after receipt of such
                      request. If Lessor accepts such offer, this Lease shall be
                      deemed to have been amended by deleting such portion from
                      the Leased Premises and by reducing the fixed rent by an
                      amount equal to the product of the fixed rent multiplied
                      by a fraction, the numerator of which shall be the
                      rentable floor area of such portion deleted from the
                      Leased Premises including the deleted portion. Thereafter,
                      for all purposes of this Lease the Leased Premises shall
                      mean the balance of the original Leased Premises demised
                      hereunder following deletion of the affected portion
                      thereof, and all additional rent payable hereunder shall
                      be adjusted pro rata, accordingly. Such amendment shall be
                      effective on the proposed effective date of the sublease
                      as specified in LESSEE's request for consent.

15.  SUBORDINATION    This lease shall be subject and subordinate to any and all
                      mortgages, deeds of trust and other instruments in the
                      nature of a mortgage, now or at any time hereafter, a lien
                      or liens on the Property of which the Leased Premises are
                      a part and the LESSEE shall, when requested, promptly
                      execute and deliver such written instruments as shall be
                      necessary to show the subordination of this lease to said
                      mortgages, deeds of trust or other such instruments in the
                      nature of a mortgage. Lessor shall obtain, from each
                      Mortgagee of the Property or Building, a non-disturbance
                      agreement for Lessee.

16.  LESSOR'S ACCESS  The Lessor or agents of the LESSOR may, at reasonable
                      times and upon reasonable not ice except in emergency,
                      enter to view the Leased Premises and may remove placards
                      and signs not approved and affixed as herein provided, and
                      make repairs and alterations to the common systems and
                      facilities and to the other portions of the

                                      - 9 -
<PAGE>

                      Leased Premises to the extent LESSEE has failed to perform
                      its obligations hereunder, all as LESSOR should reasonably
                      elect to do and may show the Leased Premises to others,
                      and at any time within three (3) months before the
                      expiration of the term, may affix to any suitable part of
                      the Leased Premises a notice for letting or selling the
                      Leased Premises or the Property of which the Leased
                      Premises are a part and keep the same so affixed without
                      hindrance or molestation.

17.  INDEMNIFICATION
     AND LIABILITY    The LESSEE shall save the LESSOR harmless from all loss
                      and damage occasioned by the use by LESSEE or escape of
                      water caused by LESSEE or by the bursting of the pies
                      caused by LESSEE, as well as from any claim or damage
                      resulting from any nuisance made or suffered on the Leased
                      Premises, unless such loss is caused by the neglect of the
                      LESSOR> The removal of snow and ice from the sidewalks
                      bordering upon the Leased Premises shall be the LESSOR's
                      responsibility.

18.  LESSEE'S
     LIABILITY
     INSURANCE        The LESSEE shall maintain with respect to the Leased
                      Premises and the Property, of which the Leased Premises
                      are a part, comprehensive public liability insurance in
                      the amount of $500,000.00 with property damage insurance
                      in limits of $100,000.00 in responsible companies
                      qualified to do business in Massachusetts and in good
                      standing therein insuring the LESSOR as well as LESSEE
                      against injury to persons or damage to property as
                      provided. The LESSEE shall deposit with the LESSOR
                      certificates for such insurance at or prior to the
                      commencement of the term, and thereafter within thirty
                      (30) days prior to the expiration of any such policies.
                      All such insurance certificates shall provide that such
                      policies shall not be cancelled without at least ten (10)
                      days prior written notice to each assured named therein.

19.  FIRE, CASUALTY
     EMINENT DOMAIN   Should a substantial portion of the Leased Premises, or of
                      the Property of which they are a part be substantially
                      damaged by fire or other casualty, or be taken by eminent
                      domain, the LESSOR may elect to terminate this lease
                      within 30 days of such fire or other casualty. When such
                      fire, casualty, or taking renders the Lease Premises
                      (including reasonable access thereto) substantially
                      unsuitable for their intended use a just and proportionate
                      abatement of rent and additional rent shall be made and
                      the LESSEE may elect to terminate this lease if:

                                     - 10 -
<PAGE>

                           (a) The LESSOR fails to give written notice within
                      thirty (30) days of its intention to restore the Lease
                      Premises, or

                           (b) The LESSOR fails to restore the Leased Premises
                      to a condition substantially suitable for their intended
                      use within one hundred eighty (180) days of said fire,
                      casualty, or taking.

                      The LESSOR reserves, and the LESSEE grants to the LESSOR,
                      all rights which the LESSEE may have for damages or injury
                      to the Leased Premises for any taking by eminent domain,
                      except for damage to the LESSEE's fixtures, property, or
                      equipment, and for LESSEE's moving expenses.

20.  DEFAULT AND
     BANKRUPTCY       In the event that:

                           (a) The LESSEE shall default in the payment of any
                      installment of rent or other sum herein specified and such
                      default shall continue for ten (10) days after written
                      notice thereof;

                           (b) The LESSEE shall default in the observance or
                      performance of any other of the LESSEE's covenants,
                      agreements, or obligations hereunder and such default
                      shall not be corrected within thirty (30) days after
                      written notice thereof or such longer time as shall be
                      reasonably required to complete such cure in the exercise
                      of due diligence; or

                           (c) The LESSEE shall be declared bankrupt or
                      insolvent according to law, or, if any assignment shall be
                      made of LESSEE's property for the benefit of creditors,
                      then the LESSOR shall have the right thereafter, while
                      such default continues, to re-enter and take complete
                      possession of the Leased Premises, to declare the term of
                      this lease ended, and remove the LESSEE's effects, without
                      prejudice to any remedies which might be otherwise used
                      for arrears of rent or other default. In lieu of re-entry,
                      LESSOR may send notice by mail terminating this lease. The
                      LESSEE shall indemnify the LESSOR against all loss of rent
                      and other payments which the LESSOR may incur by reason of
                      such termination during the residue of the term. If the
                      LESSEE shall default, after reasonable notice thereof, in
                      the observance or performance of any conditions or
                      covenants on LESSEE's part to be observed or performed
                      under or by virtue of any of the provisions in any article
                      of this lease, the LESSOR, without being under any
                      obligation to do so and without thereby waiving such
                      default, may remedy such default for the account and at
                      the expense of the LESSER. If the LESSOR makes any
                      expenditures or incurs any obligations for the payment of
                      money in connection

                                     - 11 -
<PAGE>

                      therewith, including but not limited to, reasonable
                      attorney's fees in instituting, prosecuting or defending
                      any action or proceeding, such sums paid or obligations
                      incurred with interest at the rate of two percent (2%) per
                      annum above the prime rate charged from time to time by
                      the Bank of Boston to its most credit-worthy commercial
                      customers, shall be paid to the LESSOR by the LESSEE as
                      additional rent.

21.  LATE CHARGE      If LESSEE shall fail to pay, within ten (10) days after
                      the same shall become due, any amount of fixed rent or
                      additional rent or any other amount required to be paid by
                      LESSEE hereunder, LESSEE shall pay to LESSOR, on demand
                      and in addition to such amount, a late charge equal to
                      daily interest based on a 360-day year from the date such
                      amount became due on the amount thereof from time to time
                      remaining unpaid at a per annum interest rate of two
                      percent (2%) above the prime rate charged from time to
                      time by the Bank of Boston. Such late charge shall be in
                      addition to, and not in limitation of, LESSOR's other
                      rights and remedies in the event of such late payment.

22.  NOTICE           Any notice from the LESSOR to the LESSEE relating to the
                      Leased Premises or to the occupancy thereof, shall be
                      deemed duly served, if hand delivered to the Leased
                      Premises during normal business hours addressed to the
                      LESSEE, or, if mailed to the Leased Premises, registered
                      or certified mail, return receipt requested, postage
                      prepaid addressed to the LESSEE or to such other address
                      of which Lessor has been given notice with a copy to Hill
                      & Barlow, One International Place, Boston, MA 02110, Attn:
                      Emily C. Hewitt, Esq. Any notice from the LESSEE to the
                      LESSOR relating to the Leased Premises or to the occupancy
                      thereof, shall be deemed duly served, if mailed to the
                      LESSOR by registered or certified mail, return receipt
                      requested, postage prepaid, addressed to the LESSOR at
                      such address as the LESSOR may from time to time advise in
                      writing. All notices shall be sent to the LESSOR at:

                      John Hancock Properties, Inc.
                      Two Copley Place, Suite 200
                      Post Office Box 111
                      Boston, Massachusetts 02117

                      Meredith & Grew, Incorporated
                      160 Federal Street
                      Boston, Massachusetts 02110-1701.

                      LESSEE agrees from time to time, upon not less than
                      fifteen (15) days prior written request by LESSOR, to
                      execute, acknowledge

                                     - 12 -
<PAGE>

                      and deliver to LESSOR a statement in writing certifying
                      that this Lease is unmodified and in full force and effect
                      and that LESSEE has no defenses, offsets or counterclaims
                      against its obligations to pay the fixed rent and
                      additional rent and to perform its other covenants under
                      this Lease and that there are no uncured defaults of
                      LESSOR or LESSEE under this Lease (or, if there have been
                      any modifications, that the Lease is in full force and
                      effect as modified and stating the modifications, and, if
                      there are any defenses, offsets counterclaims, or
                      defaults, setting them forth in reasonable detail), and
                      the dates to which the fixed rent, additional rent and
                      other charges have been paid. Any such statement delivered
                      pursuant to this Section 23 may be relied upon by an
                      prospective purchaser or mortgagee of the Leased Premises
                      or any prospective assignee of any mortgage of the Leased
                      Premises.

Surrender             The LESSEE shall at the expiration or other termination of
                      this lease remove all LESSEE's goods and effects from the
                      Leased Premises, (including, without hereby limiting the
                      generality of the foregoing, all signs and lettering
                      affixed or painted by the LESSEE, either inside or outside
                      the Lease Premises). LESSEE shall deliver to the LESSOR
                      the Leased Premises and all keys, locks thereto, and other
                      fixtures connected therewith and all alterations and
                      additions made to or upon the Leased Premises, in the same
                      condition as they were at the commencement of the term, or
                      as they were put in during the term hereof, reasonable
                      wear and tear and damage by eminent domain, fire or other
                      casualty only excepted. Provided LESSEE is not in default,
                      LESSEE shall be entitled to remove its equipment and trade
                      fixtures provided it shall reasonably repair any damage
                      caused there by. In the event if the LESSEE's failure to
                      remove any of LESSEE's property from the Leased Premises,
                      LESSOR is hereby authorized, without liability to LESSEE
                      for loss or damage thereto, and at the sole risk of LESSEE
                      to remove and store any of the property at LESSEE's
                      expense, or to retain the same under LESSOR's control or
                      upon reasonable notice to sell at public or private sale,
                      without notice, any or all of the property not so removed
                      and to apply the net proceeds of such sale to the payment
                      of any sum due hereunder, or upon reasonable notice to
                      destroy such property.

                      LESSOR and LESSEE each warrant to the other that they have
                      had not dealings with any broker or agent in connection
                      with this Lease other than Meredith & Grew, Inc. (the
                      "Broker") and each covenants to the other to defend with
                      counsel approved by the other, which approval shall not be
                      unreasonably withheld or delayed, hold harmless and
                      indemnify one another from and against any and all cost,
                      expense or liability for any compensation,

                                     - 13 -
<PAGE>

                      commissions and charges claimed by any broker or agent
                      with respect to their respective dealings in connection
                      with this Lease or the negotiation thereof, other than for
                      the Broker above named. LESSOR shall pay the commission of
                      the Broker above named.

                      In the event LESSEE holds, occupies or detains the
                      Premises or any part thereof after the expiration or
                      earlier termination of this Lease, without the express
                      written consent of LESSOR, LESSEE shall be deemed a
                      tenant-at-sufferance only, and such tenancy-at-sufferance
                      shall not constitute a renewal hereof or an extension for
                      any further term or the creation of a tenancy-at-will and,
                      in such event, LESSEE shall pay to LESSOR on the first day
                      of each month, in advance, fixed rent in an amount equal
                      to twice the amount of the monthly installments of fixed
                      rent, as provided in section 4 for the last full month of
                      the tenancy hereunder. Such tenancy-at-sufferance shall be
                      subject to every other term, provision, condition,
                      covenant and agreement contained herein, including without
                      limitation the obligation of LESSEE to pay all additional
                      rent as provided in this Lease. Nothing contained this
                      Section 24 shall be construed as consent by LESSOR to any
                      holding over by LESSEE and LESSOR expressly reserves the
                      right to require LESSEE to surrender possession of the
                      Leased Premises to LESSOR as provided in this Lease upon
                      the expiration or earlier termination of this Lease, to
                      commence suit at any time to recover possession of the
                      Leased Premises and recover all installments of fixed
                      rent, additional rent and other amounts and charges due
                      hereunder, and to apply payments received by LESSOR from
                      LESSEE on account and not as payment in full or in accord
                      and satisfaction.

27.  MODIFICATION
     OF AGREEMENT     This lease contains the entire agreement between the
                      parties and shall not be modified in any manner except by
                      an instrument in writing executed by the parties.

28.  GOVERNING LAW    This lease is made pursuant to and shall be governed by
                      and construed in accordance with the laws of the
                      Commonwealth of Massachusetts.

29.  SEPARABILITY     If any provision of this lease or portion of such
                      provision or the application thereof to any person or
                      circumstance is for any reason held invalid or
                      unenforceable, the remainder of the lease (including the
                      remainder of such provisions) and the application thereof
                      to the persons or circumstances shall not be affected
                      thereby.

                                     - 14 -
<PAGE>

30.  LANDLORD'S
     LIABILITY        30.1 The obligations of LESSOR hereunder shall be binding
                      upon LESSOR and each succeeding owner of LESSOR's interest
                      hereunder only during the period of such ownership, and
                      LESSOR and each succeeding owner shall have no liability
                      whatsoever except for their obligations during each such
                      respective period. LESSEE hereby agrees for itself and
                      each succeeding holder of the LESSEE's interest under this
                      Lease, or any portion thereof, that any judgment, decree
                      or award obtained against LESSOR, or any succeeding owner
                      of LESSOR's interest, which is in any manner related to
                      his Lease, the Leased Premises or the LESSEE's use or
                      occupancy of the Lease Premises or the common areas
                      adjacent thereto, whether at law or in equity, shall be
                      satisfied only out of LESSOR's (or such succeeding
                      owner's) equity at such time in the Building and the
                      Property (or, if LESSOR or such owner has disposed of its
                      interest in the Building and the Property, then only to
                      the net proceeds of such disposition) and further agrees
                      to look only to such equity or net proceeds and to no
                      other assets of LESSOR (or such succeeding owners) for
                      satisfaction.

                      30.2 If any present or future LESSOR (or any owner of
                      LESSOR's interest hereunder) is a trust or trustee or
                      trustees of a trust, a joint venture, or firm or
                      partnership general or limited, neither any trustee nor
                      any beneficiary nor any shareholder of any said trust, nor
                      any joint venture or partner of any other such entity,
                      shall be personally liable to anyone under any term,
                      condition, covenant, obligation, or claim of damage or
                      legal or equitable claim arising out of this lease or the
                      Leased Premises or out of the use or occupancy of the
                      Leased Premises or the common areas adjacent thereto.

31.  WAIVER OF
     SUBROGATION      31.1 As used in this Section, the term "waiver of
                      subrogation clause" means a clause, endorsement or other
                      provision appearing in an insurance policy which provides
                      that the insurer waives any right of subrogation it may
                      have against LESSEE (if the clause is in a policy insuring
                      LESSOR) or against LESSOR (if the clause is in a polity
                      insuring LESSEE).

                      31.2 LESSOR and LESSEE (or its sublessee or assign, as the
                      case may be) each shall attempt to have a waiver of
                      subrogation clause included in all insurance policies
                      which it maintains insuring against loss or damage to the
                      Building or the Leased Premises, as the case may be or any
                      of the contents of the Building or the Leased Premises, as
                      the case may be due to fire or any of the other risks
                      which are customarily comprehended by the term "extended
                      coverage" in endorsements to fire insurance policies. If
                      the insurer

                                     - 15 -
<PAGE>

                      charges an extra fee or premium for the waiver, the party
                      procuring the insurance shall pay any reasonable extra
                      cost for the waiver.

                      31.3 LESSOR releases LESSEE, and LESSEE releases LESSOR,
                      from all liability for loss or damages caused by fire or
                      the extended coverage casualties but this release is
                      subject to the following conditions and limitations:

                           (a) This release is effective only if, and to the
                      extent that, the loss or damage is covered by an insurance
                      policy maintained by one of the parties to this lease; and

                           (b) This release shall be effective only if the
                      insurance policy covering the loss or damage contains a
                      waiver of subrogation clause and a provision to the effect
                      that this release will not affect the validity of the
                      policy or the right of the insured to recover under the
                      policy.

                      31.4 LESSEE shall not acquire as insured under any
                      insurance carried by LESSOR or the Building any right to
                      participate in the adjustment of loss or to receive
                      insurance proceeds and agrees upon request promptly to
                      endorse LESSOR any checks or other instruments in payment
                      of loss in which LESSEE is named as payee.

32.  HAZARDOUS
     MATERIALS, OIL OR
     TOXIC SUBSTANCES LESSEE will not dump, flush, or in any way introduce any
                      hazardous materials or oil or any other toxic substances
                      into the septic, sewage or other waste disposal system
                      serving the Leased Premises (the foregoing shall not
                      prevent the introduction of such substances into a waste
                      disposal system specifically designed to receive such
                      substances so long as said system is constructed and
                      maintained in accordance with all applicable governmental
                      regulations); and in the event of any such unpermitted
                      introduction, will clean up promptly any damage occasioned
                      by such. The LESSEE further agrees it will not generate,
                      store or use (except in accordance with all applicable
                      governmental regulations) or dispose of hazardous
                      materials or oil or toxic substances in or on the Lease
                      Premises or dispose of hazardous materials or oil or toxic
                      substances from the Leased Premises to any other location,
                      except a properly approved disposal facility and then only
                      in compliance with any and all Federal, State and local
                      laws and ordinances regulating such activity. "Hazardous
                      materials", "oil", and "toxic substances", as used in this
                      Section, shall have the same meanings as defined and used
                      in the Massachusetts Oil and Hazardous Material Release
                      Prevention Act, as amended; M.G.L.

                                     - 16 -
<PAGE>

                      ch. 21E; the Comprehensive Environmental Response
                      Compensation and Liability Act of 1980, as amended, 42
                      U.S.C. Sections 9061 et seq.; in the Hazardous Materials
                      Transportation Act, 15 U.S.C. Section 180; in the Toxic
                      Substances Act, 15 U.S.C. Sections 860; et seq.; and in
                      the regulations adopted and publications promulgated
                      pursuant to said acts.

33.  OPTION TO
     EXTENT           If no default by LESSEE remains uncured beyond any
                      applicable grace or cure period at the time of the
                      exercise of the option and at the commencement of any
                      extension term, LESSEE shall have the option or to extend
                      the initial term for an additional five-year period
                      commencing September 1, 1993 and expiring on August 31,
                      1998. Annual Fixed Rent during such extension term shall
                      be the greater of (a) the sum of Annual Fixed Rent plus
                      escalations and other rent adjustments for the last year
                      of the initial term or (b) "Fair Market Rent", which shall
                      be the product of 19,250 rentable square feet and the
                      annual fair market rent per rentable square foot for
                      comparable premises in comparable areas of Boston,
                      Massachusetts for a five year term commencing September 1,
                      1993 under the terms of this lease. Rent for the extension
                      term shall also incorporate such additional financial
                      terms in the nature of rent and rent adjustments
                      customarily then being included in leases for comparable
                      premises in such areas. LESSEE shall, during the extension
                      term, pay its proportionate share (currently 31.5%) of any
                      increase in Real Estate Taxes, in either case over the
                      base year then being quoted for leases in such premises in
                      such areas. Such payment shall be made in accordance with
                      the procedures set forth in Section 6.2 and 6.9 of the
                      lease. Except as otherwise set forth herein, all terms and
                      conditions of the lease shall apply during such extension
                      term.

                      The option to extend the lease shall be exercised and Fair
                      Market Rent shall be determined as follows:

                           (a) LESSEE shall exercise its option to extend by
                      notice to LESSOR by September 1, 1992.

                           (b) LESSOR shall furnish LESSEE LESSOR'S statement of
                      Fair Market Rent and a description of any additional
                      financial terms by October 1, 1992.

                           (c) By November 1, 1992, LESSEE shall by notice
                      accept LESSOR's statement of Fair Market Rent or dispute
                      such statement and description. (Failure timely to send a
                      notice under subparagraphs (a) or (c) above, as the case
                      may be, shall constitute

                                     - 17 -
<PAGE>

                      an election not to exercise or to withdraw LESSEE'S
                      exercise of LESSEE'S extension option hereunder.)

                      In the case of dispute, the matters of Fair Market Rent
                      and the inclusion of any additional financial terms
                      promptly shall be submitted to the Boston office of the
                      American Arbitration Association ("AAA") with a request
                      for arbitration by three arbitrators who shall be MAI
                      appraisers with at least ten years experience as
                      appraisers of urban commercial real estate in the Greater
                      Boston area, such arbitration to be completed by December
                      31, 1992. If the AAA shall cease to provide arbitration
                      for commercial disputes, the dispute over Fair Market Rent
                      and the inclusion of such terms shall be submitted to any
                      successor organization proving substantially the same
                      services, and in the absence of such an organization, to a
                      court of competent jurisdiction under the arbitration act
                      of the Commonwealth of Massachusetts requesting the
                      appointment of arbitrators in accordance with the
                      provisions of the act. The cost of the arbitration shall
                      be borne equally by the parties. the lease shall be
                      extended in accordance with the arbitrators' decision.
                      Such decision may be entered and enforced by either LESSOR
                      or LESSEE in an appropriate action in a court of competent
                      jurisdiction.

                      The foregoing extension option may be exercised only by
                      AIDS Action Committee, Inc. and not by its assigns or
                      subtenants and only if AIDS Action Committee, Inc., at the
                      time of the exercise of the option and at the commencement
                      of the extension term is occupying the Leased Premises as
                      its main office.

34.  IMPROVEMENT
     ALLOWANCE        In accordance with Section 13 of the lease, LESSEE agrees
                      to deliver to LESSOR a detailed floor plan layout together
                      with working drawings, written instructions and completion
                      schedule all prepared at LESSEE's expense (herein call
                      "Lessee's Plans"), reflecting the partitions and
                      improvements desired by LESSEE in the Leased Premises.
                      Within ten (10) days of the receipt of all of Lessee's
                      Plans, LESSOR shall review for written approval Lessee's
                      Plans, such approval shall not be unreasonably withheld.
                      LESSOR shall provide LESSEE with an improvement allowance
                      of $228,144.00 (plus the reasonable cost, not to exceed
                      $14,000.00) of installation of a sprinkler system on the
                      fourth floor and upgrade of the3/4" piping on the fifth
                      floor of the Building for LESSEE's alterations and
                      improvements, including general conditions and overhead,
                      in accordance with Exhibit C and reasonable amendments
                      thereto approved by LESSEE. Disbursement for construction
                      costs shall be made jointly payable

                                     - 18 -
<PAGE>

                      to LESSEE and LESSEE's contractor from time to time (but
                      no more frequently than once every three weeks) and shall
                      be conditioned on certification by LESSOR's architect of
                      satisfactory completion of the portion of the work in
                      questions and shall be made within 10 days of LESSEE's
                      presentation of the disbursement request. Notwithstanding
                      the foregoing provision, twenty percent (20%) of the
                      improvement allowance requested in each draw shall be
                      retained by LESSOR subject to final completion in
                      accordance with the plans and specifications and evidence
                      of payment of all liens.

35.  ADDITIONAL
     PROVISIONS       It is also understood and agreed that the Rules and
                      Regulations attached hereto as Exhibit D are incorporated
                      herein by reference.

IN WITNESS WHEREOF, the parties hereto have executed this lease as an instrument
under seal on the day and year first above written.

LESSOR:                                        LESSEE:

John Hancock Mutual Life                       AIDS Action Committee, Inc.
Insurance Company

By: /s/ Carl Hohmann                           /s/ Lawrence Kessler
   --------------------------------            --------------------------------
   Carl J. Hohmann                             Larry L. Kessler
                                               its executive director
                                               hereunto duly authorized.

                                     - 19 -
<PAGE>
                                   Exhibit A

                          Floor plans of floors 3 - 5.
<PAGE>
                                    EXHIBIT B

                         For the purpose of Section 6.1:

[illegible] Expenses" shall mean all reasonable costs of LESSOR or leasing (as
the case may be), servicing, operating, [illegible] maintaining, and repairing
the building in which the [illegible] premises are located including, without
limitation, the costs [illegible] following: (i) supplies, materials and
equipment purchased [illegible] and total wage and salary costs paid to and on
account of [illegible] t to the extent engage in the operation, maintenance,
[illegible] cleaning (but only with respect to cleaning of the [illegible]
common areas) and repair of the building including [illegible] taxes and
so-called "fringe benefits"; (ii) building [illegible]furnished to tenants of
the building at LESSOR's cost and [illegible]maintenance performed by LESSOR's
employees or by [illegible] contractors under contract with LESSOR or LESSOR's
[illegible] from time to time; (iii) utilities consumed and expenses [illegible]
the operation and maintenance of the guiding facilities [illegible] thereto
including, without limitation, oil, gas, [illegible] (other than electricity to
serve the Leased Premises and [illegible] cable area in the building), water and
sewer charges [illegible] of restaurant usage), snow removal and fire
protection, [illegible] without limitation, fees paid to any governmental
[illegible] for any of the foregoing; (iv) insurance; and (v) [illegible] fees
(which terms hall include an imputed cost for a [illegible] amount of space in
the buildings; but [illegible] services, supplies, utilities and the like
provided [illegible] to the restaurant located on the first and second floors
[illegible]. If LESSOR, in its reasonable, judgment, installs a [illegible]
placement capital item in the building (including without [illegible] for the
conservation of the preservation of energy), the cost ) [illegible] amortized
over a reasonable period, including interest [illegible] then being charged by
institutional first mortgagees for [illegible] first mortgage loans on office
buildings which are [illegible] with the buildings, shall be included in
LESSOR's [illegible] expenses.

[illegible]OR's operating expenses shall not include payment of [illegible],
interest or other charges on mortgages or payment of any [illegible] LESSOR on
account of a ground lease of the land on which the [illegible] is situated or
lease of the building; costs of work or [illegible] for particular repairs
caused or occasioned by fire or [illegible] domain; advertising, legal and
marketing costs and leasing [illegible]; executive salaries of LESSOR or its
managing agents; [illegible] of so-called tenant improvements to rentable areas
in the [illegible] ; costs of services provided to fewer than all office or
costs of services provided solely to retail and/or [illegible] tenants; costs of
any capital improvement which results [illegible]material change in the size of
the Building or is not [illegible] required for continued operation of the
Building as a [illegible] older office and retail Building.

                                     - 20 -
<PAGE>

                                    EXHIBIT C

                               Feldkamp & Company

                                   Architects

20 March 1988

FIRST ESTIMATE OF CONSTRUCTION COSTS

INTERIOR RENOVATION OF FOURTH FLOOR AND UPGRADING OF FIFTH AND PARTIAL THIRD
FLOORS AT 131 CLAREDON STREET

<Table>
<S>                                                                                     <C>
-------------------------------------------------------------------------------------------------
A.   Fourth Floor
-------------------------------------------------------------------------------------------------
1.   General Conditions:  demolition of extra ductwork, items as required at            $ 3,000
     entry, insurance, bonds
-------------------------------------------------------------------------------------------------
6.   Wood and Plastics: wood trim, built-in cabinetry                                    10,000
-------------------------------------------------------------------------------------------------
7.   Thermal and Moisture:  Sound insulation at conf. rooms                                 500
-------------------------------------------------------------------------------------------------
8.   Doors and Window:  assume 16 doors @ $500, miscellaneous      tempered               8,000
     glass partitions, hardware, exit devices
-------------------------------------------------------------------------------------------------
9.   Finishes:
     a.   Gyp. board:  assume 8 offices: 2400/s f.; 3 conf. rooms:
          2100/s.f.; misc.:  2700/s.f.  Total: 7200/s.f. @ 2.50                          18,000
     b.   Floor prep:  remove tile or level @ 1.50/s.f.                                  10,000
     c.   Carpet or carpet squares: 777 yards @ $20                                      15,540
     d.   Ceramic tile @ 2 toilet rooms Revised for Handicapped                           2,500
     e.   Paint:  13,200 s.f. @ 65/s.f.                                                   8,580
     f.   Ceiling repair & acoustic treatment or lay-in tile 7000/s.f. @$2               14,000
-------------------------------------------------------------------------------------------------
10.  Specialties:  assume chalkboards, tackboards:  $1,500; handicap toilet
     accessories:  $3,000; Signage:  $2,000 demountable partitions & storage
     shelving:  Not in Contract coatracks:  $500                                          7,000
-------------------------------------------------------------------------------------------------
11.  Equipment:  Coffee room allowance                                                    1,200
-------------------------------------------------------------------------------------------------
12.  Furnishings:  blinds for 45 windows @ $30                                            1,200
     office furniture:  Not in Contract.
-------------------------------------------------------------------------------------------------
15.  Mechanical:  HVAC upgrading and ductwork changes $2/s.f.
     plumbing for Handicap toilet changes, etc.                                          15,000
     Sprinkler:  Not in Contract                                                          1,500
-------------------------------------------------------------------------------------------------
16.  Electrical:  assume 120 convenience outlets @ $35                                    4,200
     lighting and life safety                                                            22,900
     phone wiring:  assume                                                                4,000
                                                                                        -------
-------------------------------------------------------------------------------------------------
</Table>

                                     - 21 -
<PAGE>

<Table>
<S>                                                                                   <C>
-------------------------------------------------------------------------------------------------
SUBTOTAL  FOURTH FLOOR                                                                 147,120
-------------------------------------------------------------------------------------------------
B.   Fifth floor
-------------------------------------------------------------------------------------------------
New carpeting                                                                         $ 15,540
-------------------------------------------------------------------------------------------------
Repaint all surfaces, repair vinyl                                                       6,500
-------------------------------------------------------------------------------------------------
Miscellaneous moved doors and wall patching                                              2,000
-------------------------------------------------------------------------------------------------
Code requirements for handicap toilets                                                   6,000
-------------------------------------------------------------------------------------------------
Electrical revisions                                                                     3,000
                                                                                      --------
-------------------------------------------------------------------------------------------------
SUBTOTAL FIFTH FLOOR                                                                  $ 33,000
-------------------------------------------------------------------------------------------------
C.   Partial Third Floor  Allowance                                                     10,000
                                                                                      --------
-------------------------------------------------------------------------------------------------
SUBTOTAL THIRD FLOOR                                                                    10,000
-------------------------------------------------------------------------------------------------
CONTRACTORS OVERHEAD AND PROFIT @ 20%                                                   38,024
-------------------------------------------------------------------------------------------------
TOTAL PROJECT COST                                                                    $228,144
-------------------------------------------------------------------------------------------------
</Table>

                                     - 22 -
<PAGE>

                                    EXHIBIT D

                    RULES AND REGULATIONS FOR OFFICE TENANTS

1.   The sidewalks, entrances, driveways, passages, courts, elevators,
     vestibules, stairways, corridors or halls shall not be obstructed or
     encumbered by any LESSEE or used for any purpose other than for ingress to
     and egress from the Leased Premises and for delivery of merchandise and
     equipment in a prompt and efficient manner using elevators and passageways
     designated for such delivery by LESSOR. There shall not be used in any
     space, or in the public hall of the building, either by a LESSEE or by
     jobbers or others in the delivery or receipt of merchandise, any hand
     trucks, except those equipped with rubber tires and sideguards. If LESSOR
     keeps such a hand truck at the Building, it will, at reasonable times upon
     reasonable request, make such hand truck available to LESSEE.

2.   The water and wash closets and plumbing fixtures shall not be used for any
     purposes other than those for which they were designed or constructed and
     no sweepings, rubbish, rags, acids or other substances shall be deposited
     therein, and the expense of any breakage, stoppage, or damage resulting
     from the violation of this rule shall be borne by the LESSEE who, or whose
     clerks, agents, employees or visitors, shall have caused it.

3.   NO LESSEE shall sweep or throw or permit to be swept or thrown from the
     Premises any dirt or other substances into any of the corridors or halls,
     elevators, or out of the doors or windows or stairways of the Building and
     LESSEE shall not use, keep or permit to be used or kept any foul or noxious
     gas or substance in the Leased Premises or permit or suffer the Leased
     Premises to be occupied or used in a manner offensive or objectionable to
     LESSOR or other occupants of the Building by reason of noise, odors and/or
     vi rations; or interfere in any way with other tenants or those having
     business therein, nor shall any animals or birds be kept in or about the
     Building. Smoking or carrying lighted cigars or cigarettes in the elevators
     of the Building is prohibited.

4.   No awnings or other projections shall be attached to the outside walls of
     the Building without the prior written consent of LESSOR.

5.   No sign, advertisement, notice or other lettering shall be exhibited,
     inscribed, painted or affixed by any LESSEE on any part of the outside of
     the Leased Premises or the Building or the inside of the Leased Premises if
     the same is visible from the outside of the Leased Premises without the
     prior written consent of LESSOR, except that the name of LESSEE may appear
     on the entrance doors of the Leased Premises on each floor and on
     [illegible] directory which LESSOR shall maintain in the [illegible] lobby.
     In the event of the violation of the foregoing [illegible] LESSEE, LESSOR
     may remove the same without any [illegible], and may charge the expense
     incurred by such LESSEE, [illegible] be of a size, color and style approved
     by LESSOR.

     as contemplated by approved finish work, no LESSEE shall paint, drill into,
     or in any way deface any part of the Premises or the Building of which they
     form a part. No cutting or stringing of wires shall be permitted, with the
     prior written consent of LESSOR, and as LESSOR [illegible]. No LESSEE shall
     lay linoleum, or other similar

                                     - 23 -
<PAGE>
     covering, so that the same shall come in direct contact [illegible] floor
     of the Leased Premises, and, if linoleum or similar floor covering is
     desired to be used an [illegible] of builder's deadening felt shall be
     first affixed floor, by a paste or other material, soluble in water,
     [illegible] of cement or other similar adhesive material being [illegible]
     prohibited.

     LESSEE provides LESSOR with keys therefor, no additional or bolts of any
     kind shall be placed upon any of the [illegible] windows by any LESSEE, nor
     shall any changes be made [illegible] locks or mechanism thereof. Each
     LESSEE must, upon termination of his tenancy, restore to LESSOR all keys of
     [illegible], offices and toilet rooms, either furnished to,  or [illegible]
     procured by, such LESSEE, and in the event of the [illegible] any keys, so
     furnished, such LESSEE shall pay to LESSOR [illegible] THEREOF.

     [illegible], furniture, business equipment, merchandise and bulky
     [illegible] of any description shall be delivered to and removed
     [illegible] the Leased Premises only on the freight elevator and
     [illegible] the service entrances and corridors or in an [illegible] way
     reasonably approved by LESSOR and only during [illegible] in a manner
     reasonably approved by LESSOR.

     [illegible], soliciting and peddling in the Building is prohibited and each
     tenant shall cooperate to prevent the same.

     [illegible] shall have the right to prohibit any advertising by any
     [illegible] which, in LESSOR's reasonable opinion, will [illegible] the
     reputation of the Building or its desirability as a [illegible] for
     offices, and upon written notice from LESSOR, [illegible] shall refrain
     from or discontinue such advertising.

     [illegible] for customary quantities of materials used in connection
     [illegible] customary office equipment, LESSEE shall not bring or
     [illegible] it to be brought or kept in or on the Leased Premises, any
     flammable, combustible or explosive fluid, material, chemical substance, or
     cause unusual or other objectionable odors to [illegible] in or emanate
     from the Leased Premises.

                                     - 24 -
<PAGE>

                   John Hancock Mutual Life Insurance Company
                              200 Clarendon Street
                                Boston, MA 02117

                                  June 29, 1988

Aids Action Committee, Inc.
131 Clarendon Street
Boston, MA  02116

Re:  131 Clarendon Street, Boston, MA

Ladies and Gentlemen:

     Reference is made to a certain lease between Aids Action Committee, Inc.
("Tenant") and John Hancock Mutual Life Insurance Company ("Landlord") dated
this even date for the premises located at 131 Clarendon Street, Boston,
Massachusetts ("Building"). The premises ("Premises") consists of a portion of
the third floor of the Building and the entire fourth and fifth floors of the
Building.

     The parties acknowledge that the Landlord intends to install, at the
Landlord's expense, certain sprinkler devices on the third floor of the Building
and Tenant has requested, and Landlord has agreed, to postpone such installation
until calendar year 1989. In connection with such installation, Tenant hereby
agrees to provide Landlord access to the Premises for such installation and
Tenant agrees to cooperate with Landlord in such Landlord installation of the
sprinkler devices, such cooperation to include relocating Tenant employees from
the third floor during such installation to the extent necessary to affect the
installation. Landlord shall, in connection with such installation, restore the
Premises to substantially the condition the Premises were in immediately
preceding the installation, and upon the commencement of such installation shall
complete such installation within a reasonable period of time, subject to
matters outside of Landlord's control. This letter shall bind the undersigned
and its successors and assigns.

                          Sincerely,

                          JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY

                          John Hancock Properties, Inc.

                           By: Signature on File
                              --------------------------------------------------
                                Its:  Real Estate Management Officer

                                     - 25 -
<PAGE>

                           AIDS ACTION COMMITTEE, INC.

                           By: Signature on File
                              --------------------------------------------------
                                Its:

                                     - 26 -
<PAGE>

                   John Hancock Mutual Life Insurance Company
                              200 Clarendon Street
                                Boston, MA 02117

                                  June 23, 1988

Aids Action Committee, Inc.
131 Clarendon Street
Boston, MA  02116

Re:  131 Clarendon Street, Boston, MA

Ladies and Gentlemen:

     We are executing today a lease for you for premises at 131 Clarendon
Street, Boston, MA 02116. I am writing this letter to confirm our agreement that
in order to provide you with wheelchair access to the premises we will, as
Landlord, permit you to use movable wooden wedges which will permit a wheelchair
to be rolled into the building lobby from the adjacent sidewalk. We will use our
best efforts to assist you by making reasonable arrangements for the storage of
a wheelchair and such wooden edges in the building lobby or near to the building
lobby.

     It is understood that the use of the wooden wedge or wedges will not
involve any structural alteration to the building or the premises and its use
shall not unreasonably interfere with other tenants' access to or use of the
building, or violate any law, rule, regulation or ordinance affecting the
building. It is further understood that in the event we provide you with
alternative reasonable means of wheelchair access to the building lobby (at our
sole discretion), wooden wedges shall no longer be used by you for such access.
Further, in the event we provide wheelchair access to the elevators (at our sole
discretion) we shall no longer be required to use best efforts to provide
arrangements for storage of the wheelchair.

                                      Sincerely,

                                       Signature on File

                                      John Hancock Properties, Inc.

                                      John Hancock Mutual Life Insurance Company

                                     - 27 -
<PAGE>

                                  June 29, 1988

John Hancock Mutual Life Insurance Company
200 Clarendon Street
Boston, Massachusetts  02117

Re:  131 Clarendon Street, Boston, Massachusetts

Ladies and Gentlemen:

     Reference is made to a certain Lease between John Hancock Mutual Life
Insurance Company and Aids Action Committee, Inc. dated this even date for
premises located at 131 Clarendon Street, Boston, Massachusetts ("Premises").
Tenant has requested and Landlord has agreed to execute that certain Design
Affidavit ("Affidavit") attached hereto and incorporated herein by reference as
Exhibit A in order to facilitate Tenant's leasehold improvements in the
Premises. As a material inducement in Landlord's executing the Affidavit, Tenant
hereby indemnifies and holds landlord harmless from and against any and all
claims, demands, causes of action, losses, damages, liabilities, costs and
expenses asserted against or incurred by Landlord by reason of or arising out of
the breach of failure of any of the certifications set forth in the Affidavit,
except (with respect to subsection (c) of the Affidavit) for matters arising out
of existing conditions not caused by Tenant.

                                      AIDS ACTION COMMITTEE, INC.

                                      By: Signature on File
                                         ---------------------------------------
                                           Its:

                                     - 28 -
<PAGE>

                                    EXHIBIT A

FAST TRACK BUILDING PERMIT PROGRAM
FOR COMMERCIAL OFFICE BUILDINGS

DESIGN AFFIDAVIT (OWNER)

To the Inspectional Service Commissioner:

Re:  (ADDRESS)
     ---------------------------------------------------------------------------

     (WARD)
     ---------------------------------------------------------------------------

I certify that to the best of my knowledge, information and belief: (a) the
proposed work does not constitute a substantial alteration of an existing
building; (b) the proposed work does not involve a change of use, as defined in
the Boston Zoning Code and Massachusetts State Building Code; (c) that if any
violations of the building code, zoning code, or other applicable codes, laws
and regulations were discovered, the owner and/or tenant at his own expense and
without recourse to the city or any of its agencies, will correct or will have
corrected any such violations prior to the issuance of any required occupancy
permits.

Owner Name:
           ---------------------------------------------------------------------

Company Name:
             -------------------------------------------------------------------

Address:
        ------------------------------------------------------------------------

Date:
     ---------------------------------

Then personally appeared the above named __________________ and made oath that
the above statement by him is true.

                                      Before me,

                                      ------------------------------------
                                      Notary Public

                                      My commission expires

                                     - 29 -
<PAGE>

                            FIRST AMENDMENT TO LEASE

     This instrument is an Amendment to the Lease ("Lease") between John Hancock
Mutual Life Insurance Company ("Lessor") and Aids Action Committee, Inc.
("Lessee") dated this even date demising certain premises at 131 Clarendon
Street, Boston, Massachusetts ("Building"). Terms not defined herein, but
defined in the Lease, shall have the meanings given in the Lease.

                                    RECITALS:

     A. The Leased Premises comprise a portion of the third floor of the
Building and the entire fourth and fifth floors of the Building.

     B. The Lessor and Lessee desire to amend the Lease to include an additional
forty (40) rentable square feet to the Leased Premises located on the third
floor of the Building, and the Lessee desires to obtain Lessor's consent to use
a portion of the third floor for meeting purposes from the date hereof to the
date of the commencement of the Lease Term, September 1, 1988;

     NOW, THEREFORE, for good and valuable consideration, the receipt .and
sufficiency of which are hereby acknowledged, the Lease is hereby amended as
follows:

     1. The Leased Premises shall contain approximately 19,290 rentable square
feet. Exhibit A, Page A-l of the Lease is hereby deleted and replaced with
Exhibit A, Page A-l attached hereto and incorporated herein by reference.

     2. Lessee's Proportionate Share shall be 31.6%.

     3. The Annual Fixed Rent shall be as follows:

     The Lessee shall pay to the Lessor Annual Fixed Rent (herein "Fixed Rent")
     at the rate of Three Hundred Eight Thousand Six Hundred Forty and 00/100
     ($308,640.00) dollars per year, payable in advance in monthly installments'
     of Twenty Five Thousand Seven Hundred Twenty and 00/100 ($25,720.00)
     dollars due and payable on the first day of each month. Effective September
     1, 1989 Fixed Rent will increase to Three Hundred Twenty Seven Thousand
     Nine Hundred Thirty and 00/100 ($327,930.00) dollars per year payable in
     advance in monthly installments of Twenty Seven Thousand Three Hundred
     Twenty Seven and 50/100 ($27,327.50) dollars.' Effective September 1, 1990
     Fixed Rent will increase to Three Hundred Forty Seven Thousand Two Hundred
     Twenty and 00/100 ($347,220.00) dollars per year, payable in advance in
     monthly installments of Twenty Eight Thousand Nine Hundred Thirty Five and
     00/100 ($28,935.00) dollars. Effective September 1, 1991 Fixed Rent will
     increase to Three Hundred Sixty Six Thousand Five Hundred Ten and 00/100
     ($366,510.00) dollars per year(1) -- payable in advance in monthly
     installment of Thirty Thousand Five Hundred Forty Two and 50/00
     ($30,542.50) dollars. Effective September 1, 1992 Fixed Rent will increase
     to Three Hundred Eighty Five Thousand Eight Hundred and 00/100
     ($385,800.00) dollars per year, payable in advance in monthly installments
     of Thirty Two Thousand One Hundred Fifty and 00/100 ($32,150.00) dollars.

<PAGE>

     4. Lessor hereby grants to Lessee the right to use approximately 1,090
rentable square feet on the third floor of the Building ("Pre--leased Space!'),
more particularly designated on Exhibit A attached hereto and incorporated
herein by reference, from the date hereof to the Term Commencement Date of the
Lease. Lessee may use such Pre-leased Space in accordance with the terms of the
Lease, provided, however, Lessee shall not be obligated to pay to Lessor Annual
Fixed Rent, additional rent or any other .charges set forth in the Lease except
for utility charges. Lessee shall use such Pre-leased Space solely for meeting
purposes until the commencement of the Lease Term.

     Except as hereinabove amended, the Lease shall remain in full force and
effect.

     Executed as a sealed instrument this 29th day of June, 1988.

                                      AIDS ACTION COMMITTEE, INC.

                                      By: Signature on file
                                         ---------------------------------------
                                         Its:

                                      JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY

                                      John Hancock Properties, Inc.

                                      By: Signature on file
                                         ---------------------------------------
                                         Its:  Real Estate Management Officer

                                      - 2 -
<PAGE>

                     SECOND AMENDMENT TO LEASE FOR PREMISES

                         LOCATED AT 131 CLARENDON STREET

                              BOSTON, MASSACHUSETTS

     THIS SECOND AMENDMENT TO LEASE is made as of the 6th day of January, 1992
by and between JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY, a Massachusetts
corporation (hereinafter "Lessor"), with an address do Hancock Realty Investors
Incorporated, 200 Berkeley Street, 19th floor, Boston, Massachusetts 02117, and
AIDS ACTION COMMITTEE, INC., a Massachusetts corporation (hereinafter "Lessee"),
with an address at 131 Clarendon Street, Boston, Massachusetts 02116.

                              W I T N E S S E T H:

     WHEREAS Lessor and Lessee entered into a lease dated June 30, 1988 (the
"Original Lease") for certain premises located at 131 Clarendon Street, Boston,
Massachusetts, more particularly described in the Original Lease (the "Leased
Premises"); and

     WHEREAS, Lessor and Lessee amended the Original Lease by a First Amendment
To Lease dated June 29, 1988 (the "First Amendment") (the Original Lease, as
amended by the First Amendment is hereinafter referred to as the "Lease"); and

     WHEREAS, Lessor and Lessee desire to further amend the Lease to extend the
Term for five (5) additional years, to expand the Leased Premises, and to permit
Lessee to make certain improvements to the Leased Premises.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, Lessor and Lessee hereby amend the
Lease effective September 1, 1991 as follows:

     1. Section 2, PREMISES, is deleted in Its entirety and the following shall
be inserted in its place: "("Leased Premises"): That portion of 131 Clarendon
Street, Boston, Massachusetts consisting of the portion of the third floor shown
as Suites 2, 3, 4, 5, and 6, the entire fourth floor, the entire fifth floor,
and the entire sixth floor, and containing approximately 26,330 rentable square
feet as shown on the attached Exhibit A and commonly known and numbered as 131
Clarendon Street, Boston, Massachusetts 02116, together with the right to use in
common, with others entitled thereto, the alleys, loading docks, sidewalks,
lobbies, hallways stairways, and passenger and freight elevators necessary for
access to said Leased Premises, and lavatories nearest thereto."

     2. Section 3, TERM, is deleted in its entirety and the following shall be
inserted in its place: "The term of the Lease shall be for ten (10) years
commencing on September 1, 1988 and ending on August 31, 1998."

                                      - 3 -
<PAGE>

     3. At Section 4, ANNUAL FIXED RENT, the fourth and fifth sentences are
deleted in their entirety and the following shall be inserted in their place:
"Effective September 1, 1991, Fixed Rent shall be Three Hundred Ninety Four
Thousand Nine Hundred Fifty and 00/100 ($394,950.00) Dollars per year, payable
in advance in monthly installments of Thirty Two Thousand Nine Hundred Twelve
and 50/100 ($32,912.50) Dollars. Effective September 1, 1993, Fixed Rent shall
be Four Hundred Twenty One Thousand Two Hundred Eighty and 00/100 ($421,280.00)
Dollars per year, payable in advance in monthly installments of Thirty Five
Thousand One Hundred Six and 67/100 ($35,106.67) Dollars. Effective September 1,
1994, Fixed Rent shall be Four Hundred Forty Seven Thousand Six Hundred Ten and
00/100 ($447,610.00) Dollars per year, payable in advance in monthly
installments of Thirty Seven Thousand Three Hundred and 83/100 ($37,300.83)
Dollars. Effective September 1, 1995, Fixed Rent shall be Four Hundred Seventy
Three Thousand Nine Hundred Forty and 00/100 ($473,940.00) Dollars per year,
payable in advance in monthly installments of Thirty Nine Thousand Four Hundred
Ninety Five and 00/100 ($39,495.00) Dollars. Effective September 1, 1996, Fixed
Rent shall be Five Hundred Thousand Two Hundred Seventy and 00/100 ($500,270.00)
Dollars per year, payable in advance in monthly installments of Forty One
Thousand Six Hundred Eighty Nine and 11/100 ($41,689.17) Dollars. Effective
September 1, 1997, Fixed Rent shall be Five Hundred Twenty Six Thousand Six
Hundred and 00/100 ($526,600.00) Dollars per year, payable in advance in monthly
installments of Forty Three Thousand Eight Hundred Eighty Three and 33/100
($43,883.33) Dollars. Notwithstanding the foregoing, provided no default by
Lessee remains uncured beyond any applicable grace or cure period, no monthly
installments of Fixed Rent shall be due on May 1, 1992, June 1, 1992, and May 1,
1993."

     4. Section 6.1, RENT ADJUSTMENT, is amended by adding the following
language at the end of the paragraph: "Effective September 1, 1991, Lessee's
operating expense base year shall be Calendar Year 1990, and Lessee's
proportionate share of the increase in operating expenses is 43.09%, calculated
as follows: 26,330 rentable square feet in Leased Premises divided by 61,110
rentable square feet in Building."

     5. Section 6.4, RENT ADJUSTMENT, is amended by adding the following
language at the end of the paragraph: "Effective September 1, 1991, Lessee's
real estate: tax base year shall be Fiscal Year 1991, and Lessee's proportionate
share of the increase in real estate taxes is 43.09%, calculated as follows:
26,330 rentable square feet in Leased Premises divided by 61,110 rentable square
feet in Building."

     6. At Section 6.8, RENT ADJUSTMENT, the first sentence is deleted in its
entirety and the following is inserted in its place: "It is understood by the
parties hereto that there are presently four tax billing periods for each fiscal
year, namely the billing period from July 1 through September 30 of each year,
the billing, period from October 1 through December 31 of each year, the billing
period from January 1 through March 30 of each year, and the billing period from
April 1 through June 30 of each year."

     7. AS IS/SIXTH FLOOR ABATEMENT

          Lessee accepts the entire Leased Premises and the remainder of the
Building in its current "As-Is" condition. Notwithstanding anything in the Lease
or this Amendment to the

                                      - 4 -
<PAGE>

contrary, Lessee's obligation to pay the Annual Fixed Rent, additional rent for
operating expenses and the additional rent for taxes allocable to the sixth
(6th) floor of the Premises shall be abated until January 16, 1992.

     8. Section 22, NOTICE, the first sentence is deleted in its entirety and
the following is inserted in its place: "Any notice from the Lessor to the
Lessee relating to the Leased Premises or to the occupancy thereof, shall be
deemed duly served, if hand delivered to the Leased Premises during normal
business hours addressed to the Lessee, Attn: Office Services Facilities
Manager, or, if mailed to the Leased Premises, registered or certified mail,
return receipt requested, postage prepaid, addressed to the Lessee, Attn: Office
Services Facilities Manager, or to such other address of which Lessor has been
given notice with a copy to Peabody & Arnold, 50 Rowes Wharf, Boston, MA 02110,
Attn: Donald E Vaughan, Esquire " Lessor's address for notices is deleted and
hereby amended by inserting the following in its stead:

          "Hancock Realty Investors Incorporated
          200 Berkeley Street
          19th Floor
          Boston, MA 02117"

     9. Section 33, OPTION TO EXTEND, is deleted in its entirety and the
following is inserted in its place: "If no default by Lessee remains uncured
beyond any applicable grace or cure period at the time of the exercise of the
option and at the commencement of any extension term, Lessee shall have the
option to extend the initial term for an additional five-year period commencing
September 1,1998 and expiring on August 31, 2003. Annual Fixed Rent during such
extension term shall be "Fair Market Rent", which shall be the product of 26,330
rentable square feet and the annual fair market rent per rentable square foot
for comparable premises in comparable areas of Boston, Massachusetts for a
five-year term commencing September 1, 1998 under the terms of this Lease. Rent
for the extension term shall also incorporate such additional financial terms in
the nature of rent and rent adjustments customarily then being included in
leases for comparable premises in such areas. Lessee shall, during the extension
term, pay its proportionate share (currently 43.09%) of any increase in Lessor's
Operating Expenses and its proportionate share (currently 43.09%) of any
increase in Real Estate Taxes, in either case over the base year then being
quoted for leases in such premises in such areas. Such payments shall be made in
accordance with the procedures set forth in Section 6.2 and 6.9 of the Lease.
Except as otherwise set forth herein, all terms and conditions of the Lease
shall apply during such extension term.

The option to extend the Lease shall be exercised and Fair Market Rent shall be
determined as follows:

     (a) Lessee shall exercise its option to extend by notice to Lessor by
September 1, 1997.

                                      - 5 -
<PAGE>

     (b) Lessor shall furnish Lessee Lessor's statement of Fair Market Rent and
a description of any additional financial terms by October 1, 1997.

     (c) By November 1, 1997, Lessee shall by notice accept Lessor's statement
of Fair Market Rent or dispute such statement and description. (Failure timely
to send a notice under subparagraphs (a) or (c) above, as the case may be, shall
constitute an election not to exercise or to withdraw Lessee's exercise of
Lessee's extension option hereunder.)

In the case of dispute, the matters of Fair Market Rent and the inclusion of any
additional financial terms promptly shall be submitted to the Boston office of
the American Arbitration Association ("AAA") with a request for arbitration by
three arbitrators who shall be MAI appraisers with at least ten years experience
as appraisers of urban commercial real estate in the Greater Boston area, such
arbitration to be completed by December 31, 1997. If the AAA shall cease to
provide arbitration for commercial disputes, the dispute over Fair Market Rent
and the inclusion of such terms shall be submitted to any successor organization
providing substantially the same services, and in the absence of such an
organization, to a court of competent jurisdiction under the arbitration act of
The Commonwealth of Massachusetts requesting the appointment of arbitrators in
accordance with the provisions of that act. The cost of the arbitration shall be
borne equally by the parties. The Lease shall be extended in accordance with the
arbitrators' decision. Such decision may be entered and enforced by either
Lessor or Lessee in an appropriate action in a court of competent jurisdiction.

The foregoing extension option may be exercised only by AIDS Action Committee,
Inc. and not by its assigns or subtenants and only if AIDS Action Committee,
Inc., at the time of the exercise of the option and at the commencement of the
extension term is occupying the Leased Premises as its main office."

     10. Section 34, IMPROVEMENT ALLOWANCE, shall be revised by adding the
following paragraph at the end of this Section: "Lessor shall provide Lessee
with an improvement allowance not to exceed $131,650.00 for Lessee's alterations
and improvements, including general conditions and overhead, in accordance with
Exhibit C-2 and reasonable amendments thereto approved by Lessor. Disbursement
for construction costs shall be made payable to Lessee from time to time and
shall be conditioned upon Lessor's receipt of reasonably sufficient data and
information, including without limitation invoices, contracts, agreements,
cancelled checks, and other evidence of the cost and dates of such improvements,
as will permit Lessor to calculate such Improvement Allowance. Payment shall be
made to Lessee within thirty (30) days of Lessee's presentation of the
disbursement request which request shall include certification by Lessee's
architect of satisfactory completion of the portion of the work in question
along with the information listed in the preceding sentence. Once installed, the
Improvements shall be part of the Premises and the sole property of Lessor."

     11. Exhibit A, LEASED PREMISES, is deleted in its entirety and replaced
with a new Exhibit A attached hereto

     12. Exhibit C, LESSEE'S ALTERATIONS AND IMPROVEMENTS, is amended by adding
the attached Exhibit C-2.

                                      - 6 -
<PAGE>

     13. Except as herein amended, the Lease is hereby ratified and confirmed
and shall remain in full force and effect, and all of the terms of the Lease are
incorporated herein.

     EXECUTED, under seal as of the day and year first written.

                                      JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY

                                      By: Hancock Realty Investors Incorporated

                                      By: /s/Richard Lewis
                                         ---------------------------------------
                                           Richard A. Lewis
                                           Its:  Vice President

                                      AIDS ACTION COMMITTEE, INC.

                                      By: /s/Cheryl Schaffer
                                         ---------------------------------------
                                           Cheryl Schaffer
                                           Its: Deputy Executive Director
                                                hereunto duly authorized

                                      - 7 -
<PAGE>

                                   Exhibit A

                          Floor Plans for floors 3-6.

<PAGE>

                                  Exhibit C-2

                            Plans for the 3-6 floors

<PAGE>

                      THIRD AMENDMENT TO LEASE FOR PREMISES

                         LOCATED AT 131 CLARENDON STREET

                              BOSTON, MASSACHUSETTS

     THIS THIRD AMENDMENT TO LEASE is made as of the [illegible] day of
January, 1993 by and between JOHN HANCOCK MUTUAL LIFE INSURANCE
COMPANY, a Massachusetts corporation (hereinafter "Lessor"), with an address do
Hancock Realty Investors Incorporated, 200 Berkeley Street, 19th Floor, Boston,
Massachusetts 02117, and AIDS ACTION COMMITTEE, INC., a Massachusetts
corporation (hereinafter "Lessee"), with an address at 131 Clarendon Street,
Boston, Massachusetts 02116.

                                   WITNESSETH:

     WHEREAS, Lessor and Lessee entered into a lease dated June 30, 1988 (the
"Original Lease") for certain premises located at 131 Clarendon Street, Boston,
Massachusetts, more particularly described in the Original Lease (the "Leased
Premises"); and

     WHEREAS, Lessor and Lessee amended the Original Lease by a First Amendment
To Lease dated June 29, 1988 (the "First Amendment") and a Second Amendment To
Lease dated January 6, 1992 (the "Second Amendment") (the Original Lease, as
amended by the First and Second Amendments is hereinafter referred to as the
"Lease"); and

     WHEREAS, Lessor and Lessee desire to further amend the Lease to expand the
Leased Premises and to make certain improvements to the expanded Leased
Premises.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, Lessor and Lessee hereby amend the
Lease effective February 1, 1993 as follows:

     1. Section 2, PREMISES, is deleted in its entirety and the following shall
be inserted in its place: "("Leased Premises"): That portion of 131 Clarendon
Street, Boston, Massachusetts consisting of the portion of the third floor shown
as Suites 2, 3, 4, 5, and 6, the entire fourth floor, the entire fifth floor,
the entire sixth floor, and a portion of the seventh floor, and containing
approximately 28,330 rentable square feet as shown on the attached Exhibit A and
commonly known and numbered as 131 Clarendon Street, Boston, Massachusetts
02116, together with the right to use in common, with others entitled thereto,
the alleys, loading docks, sidewalks, lobbies, hallways, stairways, and
passenger and freight elevators necessary for access to said Leased Premises,
and lavatories nearest thereto."

     2. Item 3 in the Second Amendment To Lease is deleted in its entirety and
the following shall be inserted in its place: "Effective September 1, 1991,
Fixed Rent shall be Three Hundred Ninety-Four Thousand Nine Hundred Fifty and
00/100 ($394,950.00) Dollars per year, payable in advance in monthly
installments of Thirty-Two Thousand Nine Hundred Twelve and 50/100 ($32,912.50)
Dollars. Effective February 1, 1993, Fixed Rent shall be Four Hundred

                                      - 8 -
<PAGE>

Twenty-Four Thousand Nine Hundred Fifty and 00/100 ($424,950.00) Dollars per
year, payable in advance in monthly installments of Thirty-Five Thousand Four
Hundred Twelve and 50/100 ($35,412.50) Dollars Effective September 1, 1993,
Fixed Rent shall be Four Hundred Fifty-Three Thousand Two Hundred Eighty and
00/100 ($453,280.00) Dollars per year, payable in advance in monthly
installments of Thirty-Seven Thousand Seven Hundred Seventy-Three and 33/100
($37,773.33) Dollars. Effective September 1, 1994, Fixed Rent shall be Four
Hundred Eighty-One Thousand Six Hundred Ten and 00/l00 ($481,610.00) Dollars per
year, payable in advance in monthly installments of Forty Thousand One Hundred
Thirty-Four and 17/100 ($40,134.17) Dollars. Effective September 1, 1995, Fixed
Rent shall be Five Hundred Nine Thousand Nine Hundred Forty and 00/100
($509,940.00) Dollars per year, payable in advance in monthly installments of
Forty-Two Thousand Four Hundred Ninety-Five and 00/100 ($42,495.00) Dollars.
Effective September 1, 1996, Fixed Rent shall be Five Hundred Thirty-Eight
Thousand Two Hundred Seventy and 00/1 00 ($538,270.00) Dollars per year, payable
in advance in monthly installments of Forty-Four Thousand Eight Hundred
Fifty-Five and 83/100 ($44,855.83) Dollars. Effective September 1, 1997, Fixed
Rent shall be Five Hundred Sixty-Six Thousand Six Hundred and 00/100
($566,600.00) Dollars per year, payable in advance in monthly installments of
Forty-Seven Thousand Two Hundred Sixteen and 67/100 ($47,216.67) Dollars. Not
withstanding the foregoing, provided no default by Lessee remains uncured beyond
any applicable grace or cure period, no monthly installment of Fixed Rent shall
be due on May 1, 1992, June 1, 1992 and May 1, 1993. In addition, Lessee shall
receive a rent abatement of Two Thousand Five Hundred and 00/100 ($2,500.00)
Dollars per month for the months of February, March, and April, 1993."

     3. Section 6.1, RENT ADJUSTMENT is amended by adding the following language
at the end of the paragraph: "Effective February l, 1993, Lessee's operating
expense base year for the Leased Premises on the seventh floor shall be Calendar
Year 1992, and Lessee's proportionate share of the increase in operating
expenses is 3.27%, calculated as follows: 2,000 rentable square feet on the
seventh floor of the Leased Premises divided by 61,110 rentable square feet in
the Building."

     4. Section 6.4, RENT ADJUSTMENT is amended by adding the following language
at the end of the paragraph: "Effective February 1, 1993, Lessee's real estate
tax base year for the Leased Premises on the seventh floor shall be Fiscal Year
1993, and Lessee's proportionate share of the increase in real estate taxes is
3.27%, calculated as follows: 2,000 rentable square feet on the seventh floor of
the Leased Premises divided by 61,110 rentable square feet in the Building.

     5. In Item 9 in the Second Amendment To Lease, the second and fourth
sentences are deleted in their entirety and the following shall be inserted in
their place: "Annual Fixed Rent during such extension term shall be "Fair Market
Rent," which shall be the product of 28,330 rentable square feet and the annual
fair market rent per rentable square foot for comparable premises in comparable
areas of Boston, Massachusetts for a five-year term commencing September 1, 1998
under the terms of this Lease. Lessee shall, during the extension term, pay its
proportionate share (currently 46.36%) of any increase in Lessor's Operating
Expenses and its proportionate share (currently 46.36%) of any increase in Real
Estate Taxes, in either case over the base year then being quoted for leases in
such premises in such areas."

                                      - 9 -
<PAGE>

     6. Section 34, IMPROVEMENT ALLOWANCE, shall be revised by adding the
following paragraph at the end of this Section: "Lessor shall provide Lessee
with an improvement allowance not to exceed $20,000.00 for Lessee's alterations
and improvements to the Leased Premises on the seventh floor, including general
conditions and overhead, in accordance with plans which shall be submitted by
Lessee for Lessor's approval. Lessee's improvement allowance excludes costs for
electrical lighting and HVAC modifications which shall be performed by Lessor."

     7. Exhibit A, LEASED PREMISES, is deleted in its entirety and replaced with
a new Exhibit A attached hereto.

     8. Except as herein amended, the Lease is hereby ratified and confirmed and
shall remain in full force and effect, and all of the terms of the Lease are
incorporated herein.

     EXECUTED, under seal as of the day and year first written.

                                  JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY

                                  By:  Hancock Realty Investors Incorporated

                                  By: /s/ Anne L. Pierrera
                                     -------------------------------------------
                                     Anne L. Pierrera
                                     Its:  Investment Officer

                                     - 10 -
<PAGE>

                                  AIDS ACTION COMMITTEE, INC.

                                   By: /s/ Cheryl Schaffer
                                     -------------------------------------------
                                     Cheryl Schaffer
                                     Its:  Deputy Executive Director
                                           hereunto duly authorized

                                     - 11 -
<PAGE>
                                   Exhibit A
                           Floor plans for floors 3-7
<PAGE>

                     FOURTH AMENDMENT TO LEASE FOR PREMISES

                         LOCATED AT 131 CLARENDON STREET

                              BOSTON, MASSACHUSETTS

     THIS FOURTH AMENDMENT TO LEASE is made as of the 9th day of June, 1994 by
and between JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY, a Massachusetts
corporation (hereinafter "Lessor"), with an address do The Real Estate
Investment Group, 200 Berkeley Street, 19th Floor, Boston, Massachusetts 02117,
and AIDS ACTION COMMITTEE, INC., a Massachusetts corporation (hereinafter
"Lessee"), with an address at 131 Clarendon Street, Boston, Massachusetts 02116.

                                   WITNESSETH:

     WHEREAS, Lessor and Lessee entered into a lease dated June 30, 1988 (the
"Original Lease") for certain premises located at 131 Clarendon Street, Boston,
Massachusetts, more particularly described in the Original Lease (the "Leased
Premises"); and

     WHEREAS, Lessor and Lessee amended the Original Lease by a First Amendment
To Lease dated June 29, 1988 (the "First Amendment"), a Second Amendment To
Lease dated January 6, 1992 (the "Second Amendment") and a Third Amendment to
Lease dated January 11, 1993 (the "Third Amendment") (the Original Lease, as
amended by the First, Second and Third Amendments is hereinafter referred to as
the "Lease"); and

     WHEREAS, Lessor and Lessee desire to further amend the Lease to expand the
Leased Premises.

     NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, Lessor and Lessee hereby amend the
Lease effective July 1, 1994 as follows:

     1. Section2, PREMISES, is deleted in its entirety and the following shall
be inserted in its place: "("Leased Premises"): That portion of 131 Clarendon
Street, Boston, Massachusetts consisting of the entire third floor, the entire
fourth floor, the entire fifth floor, the entire sixth floor, and a portion of
the seventh floor, and containing approximately 30,160 rentable square feet as
shown on the attached Exhibit A and commonly known and numbered as 131 Clarendon
Street, Boston, Massachusetts 02116, together with the right to use in common,
with others entitled thereto, the alleys, loading docks, sidewalks, lobbies,
hallways, stairways, and passenger and freight elevators. necessary for access
to said Leased Premises, and lavatories nearest thereto."

     2. In Item 2 in the Third Amendment To Lease, the fourth, fifth, sixth and
seventh sentences are deleted in their entirety and the following shall be
inserted in their place: "Effective July 1, 1994, Fixed Rent shall be Four
Hundred Eighty-Two Thousand Five Hundred Sixty and 00/1 00 ($482,560.00) Dollars
per year, payable in advance in monthly installments of Forty Thousand Two
Hundred Thirteen and 33/100 ($40,213.33) Dollars. Effective September 1, 1994,
Fixed Rent shall be Five Hundred Twelve Thousand Seven Hundred Twenty

                                     - 12 -
<PAGE>

and 00/100 ($512,720.00) Dollars per year, payable in advance in monthly
installments of Forty-Two Thousand Seven Hundred Twenty-Six and 67/100
($42,726.67) Dollars. Effective September 1, 1995, Fixed Rent shall be Five
Hundred Forty-Two Thousand Eight Hundred Eighty and 00/100 ($542,880.00) Dollars
per year, payable in advance in monthly installments of Forty-Five Thousand Two
Hundred Forty and 00/100 ($45,240.00) Dollars. Effective September 1, 1996,
Fixed Rent shall be Five Hundred Seventy-Three Thousand Forty and 00/1 00
($573,040.00) Dollars per year, payable in advance in monthly installments of
Forty-Seven Thousand Seven Hundred Fifty-Three and 33/1 00 ($47,753.33) Dollars.
Effective September 1, 1997, Fixed Rent shall be Six Hundred Three Thousand Two
Hundred and 00/100 ($603,200.00) Dollars per year, payable in monthly
installments of Fifty Thousand Two Hundred Sixty-Six and 67/1 00 ($50,266.67)
Dollars. Notwithstanding the foregoing, provided no default by Lessee remains
uncured beyond any applicable grace or cure period, Lessee shall receive a
rent-abatement of Two Thousand Four Hundred Forty and 00/100 ($2,440.00) Dollars
per month for the months of July and August 1994, and a rent abatement of Two
Thousand Five Hundred Ninety-Two and 50/1 00 ($2,592.50) for the month of
September 1994."

     3. Section 6.1, RENT ADJUSTMENT, is amended by adding the following
language at the end of the paragraph: "Effective July 1, 1994, Lessee's
operating expense base year for 1,830 rentable square feet of the Leased
Premises on the third floor shall be Calendar Year 1993, and Lessee's
proportionate share of the increase in operating expenses is 3%, calculated as
follows: 1,830 rentable square feet on the third floor of the Leased Premises
divided by 61,110 rentable square feet in the Building."

     4. Section 6.4, RENT ADJUSTMENT, is amended by adding the following
language at the end of the paragraph: "Effective July 1, 1994, Lessee's real
estate tax base year for 1,830 rentable square feet of the Leased Premises on
the third floor shall be Fiscal Year 1994, and Lessee's proportionate share of
the increase in real estate taxes is 3%, calculated as follows: 1,830 rentable
square feet on the third floor of the Leased Premises divided by 61,110
rentable square feet in the Building.

     5. Item 5 in the Third Amendment To Lease is deleted in its entirety and
the following shall be inserted in its place: "Annual Fixed Rent during such
extension shall be "Fair Market Rent," which shall be the product of 30,160
rentable square feet and the annual fair market rent per-rentable square foot
for comparable remises in comparable areas of Boston, Massachusetts for a
five-year term commencing September 1, 1998 under the terms of this Lease.
Lessee shall, during the extension term, pay its proportionate share (currently
49.35%) of any increase in Lessor's Operating Expenses and its proportionate
share (currently 49.35%) of any increase in Real Estate Taxes, in either case
over the base year then being quoted for leases in such premises in such areas."

     6. Exhibit A, LEASED PREMISES, is deleted in its entirety and replaced with
a new Exhibit A attached hereto.

     7. Except as herein amended, the Lease is hereby ratified and confirmed and
shall remain in full force and effect, and all of the terms of the Lease are
incorporated herein.

                                     - 13 -
<PAGE>

     EXECUTED, under seal as of the day and year first written.

                                      JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY

                                      By: The Real Estate Investment Group

                                      By: /s/ Carl  J. Hohmann
                                         ---------------------------------------
                                         Carl J. Hohmann
                                         Its:  Investment Officer

                                      AIDS ACTION COMMITTEE, INC.

                                      By: /s/ Cheryl Schaffer
                                         ---------------------------------------
                                         Cheryl Schaffer
                                         Its:  Deputy Executive Director
                                               hereunto duly authorized

                                     - 14 -
<PAGE>
                                   Exhibit A
                           Floor Plans of floors 3-7.
<PAGE>

                      FIFTH AMENDMENT TO LEASE FOR PREMISES

                         LOCATED AT 131 CLARENDON STREET

                              BOSTON, MASSACHUSETTS

     THIS FIFTH AMENDMENT TO LEASE is made as of the 2nd day of December, 1997
by and between JOHN HANCOCK MUTUAL LIFE INSURANCE COMPANY, a Massachusetts
corporation (hereinafter "Lessor"), with an address c/a The Real Estate
Investment Group, 200 Clarendon Street, T-53, Boston, Massachusetts 02117, and
AIDS ACTION COMMITTEE OF MASSACHUSETTS, INC., a Massachusetts corporation
(hereinafter "Lessee"), with an address at 131 Clarendon Street, Boston,
Massachusetts 02116.

                                   WITNESSETH:

     WHEREAS, Lessor and Lessee entered into a lease dated June 30, 1988 (the
"Original Lease") for certain premises located at 131 Clarendon Street, Boston,
Massachusetts, more particularly described in the Origin Lease (the "Leased
Premises"); and

     WHEREAS, Lessor and Lessee amended the Original Lease by a First Amendment
to Lease dated June 29, 1988 (the "First Amendment"), a Second Amendment to
Lease DATED January 6, 1992 (the "Second Amendment"), a Third Amendment to Lease
dated January 11, 1993 (the "Third Amendment") and a Fourth Amendment to Lease
dated June 9, 1994 (the "Fourth Amendment"), (the Original Lease, as amended by
the First, Second, Third and Fourth Amendments is hereinafter referred to as the
"Lease"); and

     WHEREAS, Lessor and Lessee desire to further amend the Lease to extend the
Term for five (5) additional years, to downsize the Leased Premises, and to make
certain improvements to the Leased Premises.

     NOW THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, Lessor and Lessee hereby amend the
Lease effective September 1, 1998 as follows:

     1. Section 2, Premises, is deleted in its entirety and the following shall
be inserted in its place: ("Leased Premises"): That portion of 131 Clarendon
Street, Boston, Massachusetts consisting of the entire third floor, the entire
fourth floor, the entire fifth floor and the entire sixth floor and containing
approximately 28,160 rentable square feet as shown on the attached EXHIBIT A and
commonly known and numbered as 131 Clarendon Street, Boston, Massachusetts
02116, together with the right to use in common, with others entitled thereto,
the alleys, loading docks, sidewalks, lobbies, hallways, stairways, and
passenger and freight elevators necessary far access to said Leased Premises,
and lavatories nearest thereto."

     2. Item 2 in the Second Amendment to Lease is deleted in its entirety and
the following shall be inserted in its place: The term of the Lease shall be for
five (5) years commencing on September 1, 1998 and ending on August 31, 2003."

                                     - 15 -
<PAGE>
     3. Item 2 in the Fourth Amendment To Lease is deleted in its entirety and
the following shall be inserted in its place: "Effective September 1,1998, Fixed
Rent shall be Five Hundred Ninety-One Thousand Three Hundred Sixty and 00/100
($591,360.00) Dollars per year, payable in advance in monthly installments of
Forty-Nine Thousand Two Hundred Eighty and 00/100 ($49,280.00)Dollars. Effective
September 1, 1999, Fixed Rent shall be Six Hundred Nineteen Thousand Five
Hundred Twenty and 00/100 ($619,520.00) Dollars per year, payable in advance in
monthly installments of Fifty-One Thousand Six Hundred Twenty-Six and 67/100
($51,626.67) Dollars. Effective September 4, 2000, Fixed Rent shall be Six
Hundred Forty-Seven Thousand Six Hundred Eighty and 00/100 ($647,680.00) Dollars
per year, payable in advance in monthly installments of Fifty-Three Thousand
Nine Hundred Seventy-Three and 33/100 ($53,973.33) Dollars. Effective September
1, 2001, Fixed Rent shall be Six Hundred Seventy-Five Thousand Eight Hundred
Forty and 00/100 ($675,840.00) Dollars per year, payable in advance in monthly
installments of Fifty-Six Thousand Three Hundred Twenty and 00/100 ($56,320.00)
Dollars. Effective September 1, 2002, Fixed Rent shall be Seven Hundred Four
Thousand and 001100 ($704,000.00) Dollars per year, payable in advance in
monthly installments of Fifty-Eight Thousand Six Hundred Sixty-Six and 67/100
($58,666.67) Dollars."

     4. Section 6.1, RENT ADJUSTMENT is amended by adding the following language
at the end of the paragraph: "Effective September 1, 1998, Lessee's operating
expense base year for the Leased Premises shall be Calendar Year 1998, and
Lessee's proportionate share of the increase in operating expenses is 46.08%,
calculated as follows: 28,160 rentable square feet in the Leased Premises
divided by 61,110 rentable square feet in the Building."

     5. Section 6.4, RENT ADJUSTMENT, is amended by adding the following
language at the end of the paragraph: "Effective September 1,1998, Lessee's real
estate tax base year for the Leased Premises shall be Fiscal Tax Year 1999, and
Lessee's proportionate share of the increase in real estate taxes is 46.08%,
calculated as follows: 28,160 rentable square feet in the LEASED Premises
divided by 61,110 rentable square feet in the Building.

     6. Section 33, OPTION TO EXTEND. Item 9 in the Second Amendment to Lease,
Item 5 in the Third Amendment to Lease, and Item 5 in the Fourth Amendment to
Lease are deleted in their entirety.

     7. Section 34, IMPROVEMENT ALLOWANCE. Item 10 in the Second Amendment to
Lease and Item 6 in the Third Amendment to Lease are deleted in their entirety.

     8. Lessor and Lessee represent and warrant to each other that they have
dealt only with Meredith & Grew, Inc. ("Lessor's Broker") and Spaulding & Slye
"Lessee's Broker") in the negotiation of this Fifth Amendment, Each party agrees
to defend, indemnify and hold the other party harmless from and against any
claim, liability, cost or expense siting from a breach of the foregoing
representation. Lessor shall make payment of the brokerage fee due to Lessor's
Broker pursuant to amid in accordance with a separate agreement between Lessor
and Lessor's Broker. Lessee hereby agrees to indemnify and hold Lessor and
Lesson agent harmless of and from any and all damages, losses, costs or expenses
(including without limitation, all reasonable attorney's fees and disbursements)
by reason of any claim of or liability to any other broker or other person
(other than Lessor's Broker and Lessor's Broker) claiming through Lessee and
arising out of or in connection with the negotiation, execution and delivery of
this Fifth

                                     - 16 -
<PAGE>

Amendment Additionally, Lessee acknowledges and agrees that Lessor shall have no
obligation for payment of any brokerage fee or similar compensation to any
person with whom Lessee has dealt or may in the future deal with respect to
leasing of any additional or expansion space in the Building or renewals or
extensions of this Lease (other than Lessor's Broker or other persons with whom
Lessor has dealt or with whom Lessor may deal in the future). Notwithstanding
the foregoing Lessor shall pay Lessee's Broker a brokerage fee equal to
$57,305.00 plus an additional fee of $27,175.00. Fifty percent (50%) of such
brokerage fees shall be paid upon the execution of this Fifth Amendment, and
fifty percent (50%) shall be paid upon the term commencement of this Fifth
Amendment. Lessee shall reimburse Lessor the sum of $27,175.00 which shall be
amortized over the term of the Lease earning a ten percent (10%) interest rate.
Lessee shall pay as additional rent on account of which reimbursement the amount
of $577.39 per month throughout the Lease Term.

     9. Lessor shall repair the air conditioning water leakage and shall replace
the damaged ceiling tiles on the fourth and fifth floors of the Leased Premises
to Lessor's and Lessee's satisfaction. Lessor shall renovate the restrooms on
the fourth and sixth floors of the Leased Premises which shall include replacing
the ceramic tiles, sinks, and counters, refurbishing the toilet partitions, and
painting the restroom walls. Subject to causes beyond Lessor's control, Lessor
shall complete such work on or before September 1, 1998.

     10. Exhibit A, LEASED PREMISES. is deleted in its entirety and replaced
with a new Exhibit A attached hereto.

     11  Except as herein amended, the Lease is hereby ratified and confirmed
and shall remain in full force and effect, and all of the terms of the Lease are
incorporated herein.

     EXECUTED, under seal as of the day and year first written.

                                              JOHN HANCOCK MUTUAL LIFE INSURANCE
                                              COMPANY

                                              By: /s/ Anne W. Comstock
                                                 -------------------------------
                                                 Anne W. Comstock
                                                 Its:  Senior Investment Officer

                                     - 17 -
<PAGE>

                                              AIDS ACTION COMMITTEE OF
                                              MASSACHUSETTS, INC.

                                              By: /s/ Mary Ann Kowalski
                                                 -------------------------------
                                                 Mary Ann Kowalski
                                                 Director of Administration and
                                                 Human Resources

                                     - 18 -
<PAGE>
                                   Exhibit A
                                   ---------

                          Floor plans for floors 3-6.

<PAGE>

                                    EXHIBIT B

                               FLOOR PLAN SHOWING

                               SUBLEASED PREMISES

                                 [See Attached]

                                     - 19 -
<PAGE>

                                    EXHIBIT C

                            FORM OF LETTER OF CREDIT

                                 [See Attached]

                                     - 20 -
<PAGE>

<Table>
<Caption>
SILICON VALLEY BANK                                           APPLICATION FOR STANDBY LETTER OF CREDIT
-------------------------------------------------------------------------------------------------------
<S>               <C>                                <C>                        <C>
LOCATION          Santa Clara                        DATE                       12/19/00
-------------------------------------------------------------------------------------------------------
                                                                                For Bank Use Only
To:  Silicon Valley Bank                           ----------------------------------------------------
                                                     L/C No.
                                                   ---------------------------------------------------

Please issue an irrevocable standby letter of credit as shown on this application by Full Tex
Teletransmission or Express Mail.
--------------------------------------------- ---------------------------------------------------------
   For Account of (Applicant, Name and               In Favor of (Beneficiary, Name and
    Address)                                         Address)

ViaCell, Inc.                                        AIDS Action Committee, Inc.

551 Boylston Street, Suite 40                        131 Clarendon Street

Boston, MA 02116                                     Boston, MA 02116
=======================================================================================================
                                                                 Expiration Date

                                                      To expire on February 20, 2002, with
                                                             automatic renewals on a
                     $200,640.00                         year-to-year basis, but in no
                                                       event shall the Letter of Credit be
                                                          automatically renewed beyond
                                                               September 30, 2003
-------------------------------------------------------------------------------------------------------
</Table>

Available by drafts at sight on you, your branch or your correspondent at your
option or you may waive draft requirement. Documents required (should clearly
reflect beneficiary's right or reason for drawing):

--------------------------------------------------------------------------------
                               See Attached Draft
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
All documents will be sent in one-cover by airmail unless stated otherwise under
Special instructions. Special Instructions:
--------------------------------------------------------------------------------

                                     - 21 -
<PAGE>

--------------------------------------------------------------------------------
This Letter of Credit is to be automatically renewed on February 20, 2002 and on
a yearly basis thereafter. But, in no event shall the Letter of Credit be
automatically renewed beyond September 30, 2003
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
The opening of this credit is subject to the terms and conditions of the Standby
Letter of Credit (the Agreement") on the reverse. If this application is signed
by more than one person, the Agreement will be the contract of the signers both
as individuals and as a group.

I have read and agree to the terms and conditions on the reverse.

--------------------------------------------------------------------------------
NAME OF APPLICANT       SIGNATURE                     TITLE
--------------------------------------------------------------------------------
    ViaCell, Inc.       /s/ Marc Beer                 Chief Executive Officer

                        -------------------------------------------------------

--------------------------------------------------------------------------------
                        SIGNATURE                     TITLE
--------------------------------------------------------------------------------
                                                      Treasurer
                        /s/ Signature on File
--------------------------------------------------------------------------------

                                     - 22 -
<PAGE>

--------------------------------------------------------------------------------
                              TERMS AND CONDITIONS

     1. Applicant will reimburse Silicon Valley Bank ("Banks"), on demand in
U.S. Dollars, the amount required to pay each draft or instrument in connection
with the Letter of Credit (the "Credit"). If the Credit is Issued in a foreign
currency, applicant will pay the U.S. Dollar equivalents (as determined by Bank)
of the foreign currency amounts of all drawings under the Credit. In addition to
such reimbursement, Applicant will pay Bank, on demand, interest (on the amount
disbursed by Bank to pay each instrument) at a per annum rate equal to Bank's
Prime Rate from time to time In effect plus %. Interest shall be calculated for
the actual number of days from the date of payment of the instrument to the date
of reimbursement on the basis of a 360 day year. Applicant authorizes and
directs Bank to debit Applicants deposit accounts with the Bank to satisfy
Applicants reimbursement obligations hereunder (including any interest thereon).
Any such debit shall constitute a payment on the reimbursement debt of Applicant
created under this Section 1. Notwithstanding anything to the contrary herein.
If. Applicants reimbursement obligations hereunder is a sublimit under an
already existing loan, the time of reimbursement and the Interest rate charge
shall be governed by the repayment terms under such loan to the extent that such
tears are Inconsistent with the, reimbursement terms under this Application, if
Applicant Is party to a Loan Agreement with Bank, the terms set forth therein
(including, without limitation, any terms of the Loan Agreement or ancillary
agreements relating to collateral) shall remain in full force and effect so long
as Applicant owes obligations to Bank in connection with this Credit Applicant
will comply with all governmental exchange regulations now or hereafter
applicable to the Credit or Instruments or payments related thereto and will pay
Bank, on demand, in United States currency, such amount as Bank may be required
to expend on account of such regulations. Upon the occurrence of any one or more
of the Events of Default described in paragraph 7 below, Applicant will pay Bank
a sum equal to Bank's outstanding liability under the Credit.

     2. Applicant will pay Bank, on demand, Banks commission, interest where
chargeable, and all charges, expenses (including attorneys' fees), taxes and
fees paid or incurred by Bank in connection with the Credit and the enforcement
of Bank's rights hereunder.

     3. Applicant agrees to hold Bank and its correspondents harmless against
and reimburse it for any claim, loss, liability, cost or damage (including
attorneys' fees) arising from or hi connection with the Credit if any law or
regulation or the Interpretation thereof by arty court or administrative or
governmental authority shall either (I) impose, modify or deem applicable any
reserve, special deposit, or similar requirement against letters of credit
issued by, or assets held by, or deposits in or for the account of, Bank or (H)
impose on Bank any insurance premium or other condition regarding the Credit and
the result shall be to increase the costs of issuing or maintaining the Credit
over that which Bank assumed In determining its fees as provided for shove,
then, upon written notice and demand by Bank, Applicant shall pay to Bank, from
time to time as specified by Bank, additional amounts which shall be sufficient
to compensate Bank for such increased cost.

     4. The Uniform Customs aid Practice for Documentary Credits (1993
Revision), International Chamber of Commerce, Publication No. 500 and later
revisions adhered to by Bank, shall govern the Credit Neither Bank nor Its
correspondents shall be responsible for the condition, quality or delivery of
the property to which the Credit or any documents purportedly relate, or the
sufficiency, validity or genuineness of documents (including forgeries and
fraud) or insurance any delay, default or fraud by the shipper or others In
connection with the property or delay in arrival or failure to arrive of either
property or documents; any delay in giving or failure to give notice of arrival
or other notices; the validity or sufficiency of any endorsements; any error,
omission, or delay in giving or failure to give notice of arrival or other
notices; any error, omission, or delay in transmission of any messages. Any
action taken, or any failure to act, by Bank or any correspondent with the
Credit or the relative instruments, documents or property, if in good faith,
shall be binding on Applicant and shall not place Bank or any correspondent
under any liability to Applicant or others.

     5. As security for the payment or performance of any or all of Applicant's
obligations and liabilities hereunder, Applicant grants Bank a security interest
in the following accounts: _____________________________________________________

     6. We certify that the Board of Directors of Applicant has duly authorized
the officer(s) signing below to execute and deliver this Application to Bank. We
certify that the Board has authorized Applicant to borrow money from Bank, to
request Bank to issue the Credit and to reimburse Bank for all amounts paid by
Bank in connection with the Credit, all on terms agreed to from time to time, to
grant security for all obligations owing to Bank, and to execute and deliver
such documents, and take such other actions, as we necessary or appropriate in
connection with the performance of this Agreement. We certify that all the
resolutions authorizing the foregoing remain in full force and effect.

     7. Each of the following shall constitute an Event of Default under this
Agreement (a) if Bank shall in good faith deem itself Insecure at any time; (b)
if any of the obligations or liabilities of Applicant to Bank hereunder or under
any other agreement between Applicant and Bank shall not be paid or performed
when due; (c) if Applicant shall become insolvent (d) If a petition shall be
filed by or against Applicant for arty relief under any bankruptcy laws or any
law relating to the relief of debtors; or (e) if any governmental authority,
receiver or court shall take possession of or exercise control over any
substantial part of the property of Applicant. Upon occurrence of an Event of
Default, unless Bank shall otherwise elect, any and all obligations and
liabilities of Applicant to Bank, whether now existing or hereafter incurred,
shall become due and payable without notice and Bank may exercise all the
remedies of a secured party under Division 9 of the California Uniform
Commercial Code.

By: /s/ Marc Beer CEO                      By: /s/ Mary Thistle
   -------------------------------            ---------------------------

Name:            Marc Beer                 Name:    Mary Thistle
     -----------------------------              -------------------------

Title:   Chief Executive Officer           Title:   Treasurer
      ----------------------------               ------------------------
       (President or Vice President)            (Secretary, Asst. Secretary,
                                                 CFO or Treasurer)

                                     - 23 -
<PAGE>

                LETTER OF CREDIT FACSIMILE TRANSMISSION AGREEMENT

ViaCell, Inc.

ViaCell, Inc. wants Silicon Valley Bank ("Bank") to accept and to act on any
instructions in ViaCell's name that Bank receives by facsimile transmission (the
"FAXed Application") about letters of credit ("LC's") including, without
limitation, applications to issue or amend LC's.

Because Bank cannot verify that signatures and other information on FAXed
Applications are authorized or original, Bank will accept FAXed Applications
only if Client agrees as follows:

1. Bank may issue or amend LCs or otherwise act on instructions received by
FAXed Applications. Client accepts all risks that FAXed Applications are not
genuine, accurate or authorized.

2. Bank is not liable for damages, losses or costs of any kind (including
attorney fees) from acting or refusing to act based on FAXed Applications unless
Bank is guilty of gross negligence or willful misconduct.

3. ViaCell, Inc. will indemnify Bank and hold it harmless from any damages
losses or costs of any kind (including attorney fees) from acting or for
refusing to act based on FAXed Applications except if Bank is guilty of gross
negligence or willful misconduct.

4. Either party may terminate this Agreement at any time, but each remains
liable for LC's issued before the Agreement terminates.

5. California law governs this Agreement.

/s/ Marc Beer CEO
--------------------------------
ViaCell, Inc.

/s/ Mary Thistle
--------------------------------
Mary Thistle, Treasurer

           12/28/00
--------------------------------
Date

                                     - 24 -
<PAGE>

                             CERTIFICATE OF DEPOSIT

                               Authorization form

This letter is to authorize a Certificate of Deposit to be set up for VIACELL,
INC.

Account Information

     Please set up this certificate of deposit for: $200,640.00.

Please take the funds from SVB account #3300210718.

Term in days 365.
             ---

INTEREST PAYMENT:  Capitalize at maturity Yes  X              No
                                              ---                ---

     Transfer at Maturity to account #3300210718

     Transfer Monthly* to account # NA
                                    --

     *For terms equal to or greater than 90 days

     Date Opened:
                 --------------------------------

     Authorized signer  /s/ Mary Thistle
                      --------------------------------------------

     Printed Name Mary Thistle, Vice President of Finance and Treasurer

     Phone Number 617-266-9255 x 133

     Contact Name Mary Thistle or Jola McGrath (Controller) x 142

Silicon Valley Bank is authorized to open this certificate of deposit for:

          Letter of Credit         X
                           ------------------

          Cash management
                          -------------------

          Trade finance
                        ---------------------

          Notes
                -----------------------------

          Other
                -----------------------------

          3rd party
                    -------------------------

                                     - 25 -
<PAGE>

                         STANDBY LETTER OF CREDIT DRAFT

IRREVOCABLE STANDBY LETTER OF CREDIT NO.  SVB00ISXXX

DATE:     December 15, 2000

BENEFICIARY:

AIDS Action Committee, Inc.
131 Clarendon Street
Boston, MA 02116

AS "LANDLORD"

APPLICANT:

ViaCell, Inc.
551 Boylston Street, Suite 40
Boston, MA 02116

AS "TENANT"

AMOUNT:  US Two Hundred thousand, six hundred and forty AND 00/100 U.S. DOLLARS)

EXPIRATION DATE:

--------------------------------------------------------------------------------
                       $200,640 through February 20, 2002
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

--------------------------------------------------------------------------------

LOCATION: AT OUR COUNTERS IN SANTA CLARA, CALIFORNIA

DEAR SIR/MADAM:

WE HEREBY ESTABLISH OUR IRREVOCABLE STANDBY LETTER OF CREDIT NO. SVB001 IN YOUR
FAVOR AVAILABLE BY YOUR DRAFTS DRAWN ON US AT SIGHT AND ACCOMPANIED BY THE
FOLLOWING DOCUMENTS:

1. THE ORIGINAL OF THIS LETTER OF CREDIT AND ALL AMENDMENT(S), IF ANY.

                                     - 26 -
<PAGE>

2. A DATED CERTIFICATION FROM THE BENEFICIARY SIGNED BY AN AUTHORIZED OFFICER,
   FOLLOWED BY ITS DESIGNATED TITLE, STATING THE FOLLOWING:

     "THE AMOUNT REPRESENTS FUNDS DUE AND OWING TO US PURSUANT TO THE TERMS OF
     THAT CERTAIN SUBLEASE BY AND BETWEEN AIDS ACTION COMMITTEE, INC. AS
     SUBLANDLORD, AND VIACELL, INC. AS SUBTENANT"

PARTIAL DRAWS ARE ALLOWED. THIS LETTER OF CREDIT MUST ACCOMPANY ANY DRAWINGS
HEREUNDER FOR ENDORSEMENT OF THE DRAWING AMOUNT AND WILL BE RETURNED TO THE
BENEFICIARY UNLESS IT IS FULLY UTILIZED.

DRAFT(S) AND DOCUMENTS MUST INDICATE THE NUMBER AND DATE OF THIS LETTER OF
CREDIT.

THIS LETTER OF CREDIT SHALL BE AUTOMATICALLY EXTENDED FOR AN ADDITIONAL PERIOD
OF ONE YEAR, WITHOUT AMENDMENT, FROM THE PRESENT OR EACH FUTURE EXPIRATION DATE
UNLESS AT LEAST SIXTY (60) DAYS PR1OR TO THE THEN CURRENT EXPIRATION DATE WE
NOTIFY YOU AND THE APPLICANT BY REGISTERED MAIL/OVERNIGHT COURIER SERVICE AT THE
ABOVE ADDRESSES THAT THIS LETTER OF CREDIT WILL NOT BE EXTENDED BEYOND THE
CURRENT EXPIRATION DATE. IN NO EVENT SHALL THIS LETTER OF CREDIT BE
AUTOMATICALLY EXTENDED BEYOND September 30,2003.

THIS LETTER OF CREDIT MAY ONLY BE TRANSFERRED IN ITS ENTIRETY BY THE ISSUING
BANK UPON OUR RECEIPT OF THE ATTACHED "EXHIBIT A" DULY COMPLETED AND EXECUTED BY
THE BENEFICIARY AND ACCOMPANIED BY THE ORIGINAL LETTER OF CREDIT AND ALL
AMENDMENTS, IF ANY, WITH THE PAYMENT OF OUR TRANSFER FEE OF 1/4 OF 1% OF THE
TRANSFER AMOUNT (MINIMUM USD 250.00).

ALL DEMANDS FOR PAYMENT SHALL BE MADE BY PRESENTATION OF THE ORIGINAL
APPROPRIATE DOCUMENTS PRIOR TO 10:00 A.M. CALIFORNIA TIME, ON A BUSINESS DAY AT
OUR OFFICE (THE "BANKS OFFICE") AT: SILICON VALLEY BANK 3003 TASMAN DRIVE, SANTA
CLARA, CA 95054, ATTENTION: STANDBY LETTER OF CREDIT NEGOTIATION SECTION OR BY
FACSIMILE TRANSMISSION AT: (408) 654-6211 OR (408) 969-6510; AND SIMULTANEOUSLY
UNDER TELEPHONE ADVICE TO: (408) 654-7120 OR (408) 654-3052), ATTENTION: STANDBY
LETTER OF CREDIT NEGOTIATION SECTION WITH ORIGINALS TO FOLLOW BY OVERNIGHT
COURIER SERVICE; PROVIDED, HOWEVER, THE BANK WILL DETERMINE HONOR OR DISHONOR ON
THE BASIS OF PRESENTATION BY FACSIMILE ALONE, AND WILL NOT EXAMINE THE
ORIGINALS.

PAYMENT AGAINST CONFORMING PRESENTATIONS HEREUNDER SHALL BE MADE BY BANK DURING
NORMAL BUSINESS HOURS OF THE BANKS OFFICE WITHIN TWO (2) BUSINESS DAYS AFTER
PRESENTATION.

                                     - 27 -
<PAGE>

WE HEREBY AGREE WITH THE DRAWERS, ENDORSERS AND BONAFIDE HOLDERS THAT THE DRAFTS
DRAWN UNDER AND IN ACCORDANCE WITH THE TERMS AND CONDITIONS OF THIS LETTER OF
CREDIT SHALL BE DULY HONORED UPON PRESENTATION TO THE DRAWEE, IF NEGOTIATED ON
OR BEFORE THE EXPIRATION DATE OF THIS CREDIT.

THIS LETTER OF CREDIT IS SUBJECT TO THE UN1FORM CUSTOMS AND PRACTICE FOR
DOCUMENTARY CREDITS (1993 REVISION), INTERNATIONAL CHAMBER OF COMMERCE,
PUBLICATION NO. 500.

--------------------------------            ------------------------------------
AUTHORIZED SIGNATURE                        AUTHORIZED SIGNATURE

                                     - 28 -
<PAGE>

                                   EXHIBIT "A"

DATE:

TO:  SILICON VALLEY BANK
     3003 TASMAN DRIVE
     SANTA CLARA, CA 95054

     ATTN:     INTERNATIONAL DIVISION
               STANDBY LETTERS OF CREDIT

RE:  STANDBY LETTER OF CREDIT
     NO.       ISSUED BY
     SILICON VALLEY BANK, SANTA CLARA
     L/C AMOUNT:

GENTLEMEN:

FOR VALUE RECEIVED, THE UNDERSIGNED BENEFICIARY HEREBY IRREVOCABLY TRANSFERS TO:

(NAME OF TRANSFEREE)

(ADDRESS)

ALL RIGHTS OF THE UNDERSIGNED BENEFICIARY TO DRAW UNDER THE ABOVE LETTER OF
CREDIT UP TO ITS AVAILABLE AMOUNT AS SHOWN ABOVE AS OF THE DATE OF THIS
TRANSFER.

BY THIS TRANSFER, ALL RIGHTS 'OF THE UNDERSIGNED BENEFICIARY IN SUCH LETTER OF
CREDIT ARE TRANSFERRED TO THE TRANSFEREE. TRANSFEREE SHALL HAVE THE SOLE RIGHTS
AS BENEFICIARY THEREOF, INCLUDING SOLE RIGHTS RELATING TO ANY AMENDMENTS,
WHETHER INCREASES OR EXTENSIONS OR OTHER AMENDMENTS, AND WHETHER NOW EXISTING OR
HEREAFTER MADE. ALL AMENDMENTS ARE TO BE ADVISED DIRECT TO THE TRANSFEREE
WITHOUT NECESSITY OF ANY CONSENT OF OR NOTICE TO THE UNDERSIGNED BENEFICIARY.

                                     - 29 -
<PAGE>

THE ORIGINAL OF SUCH LETTER OF CREDIT IS RETURNED HEREWITH, AND WE ASK YOU TO
ENDORSE THE TRANSFER ON THE REVERSE THEREOF, AND FORWARD IT DIRECTLY TO THE
TRANSFEREE WITH YOUR CUSTOMARY NOTICE OF TRANSFER.

SINCERELY,

--------------------------------
(BENEFICIARY'S NAME)

--------------------------------
SIGNATURE OF BENEFICIARY

--------------------------------
SIGNATURE AUTHENTICATED

--------------------------------
(NAME OF BANK)

--------------------------------
AUTHORIZED SIGNATURE

                                     - 30 -
<PAGE>

                         CORPORATE BORROWING RESOLUTION

Borrower:

ViaCell, Inc.                                              Silicon Valley Bank
554 Boylston Street, Suite 40                              3003 Tasman Drive
Boston, MA 02116                                           Santa Clara, CA 95054

     I, Michael Lytton, being the duly elected Secretary of ViaCell, Inc. (the
"Company"), a Delaware corporation, hereby certify in such capacity that:

     1. The Board of Directors of the Company, at a duly called meeting of such
Board of Directors held on November 15, 2000, adopted the resolutions set forth
in Exhibit A attached hereto, which have not been amended or repealed in any
respect since such date, and all of which remain in full force and effect as of
the date hereof.

     2. The following persons are duly elected, qualified and acting officers of
the Company and occupy the offices set opposite their respective names, and that
the signatures set opposite their names are the true signatures of said
officers:

           NAME              OFFICE                     SIGNATURE
           ----              ------                     ---------

           Marc Beer         Chief Executive Officer    /s/ Marc Beer
                                                        ------------------------

           Mary Thistle      Treasurer                  /s/ Mary Thistle
                                                        ------------------------

     IN WITNESS WHEREOF, I have signed this certificate this ______ day of
December, 2000.

                                                        ------------------------
                                                        Michael Lytton
                                                        Secretary

                                     - 31 -
<PAGE>

                                  VIACELL, INC.

                RESOLUTIONS ADOPTED AT A MEETING OF THE BOARD OF
                         DIRECTORS ON NOVEMBER 15, 2000

APPROVAL OF CORPORATE ACCOUNTS AT FINANCIAL INSTITUTIONS

RESOLVED:             That each of the Chief Executive Officer, the Chief
                      Financial Officer or the Treasurer acting singly, be and
                      hereby is authorized and empowered on behalf of the
                      Company to open accounts at one or more financial
                      Institutions including but not limited to brokerage houses
                      ("FINANCIAL INSTITUTIONS"), for the investment of the
                      Company's cash assets in securities or other property, in
                      the name and on behalf of the Company as they may deem
                      necessary.

FURTHER

RESOLVED:             That each of the Chief Executive Officer, the Chief
                      Financial Officer or the Treasurer, acting singly, be and
                      hereby is authorized and empowered on behalf of the
                      Company to establish and maintain accounts with such money
                      market funds (the "FUNDS") as they may determine for and
                      in the name of the Company or any of its subsidiaries.
                      Each Fund is authorized to accept at any time for the
                      credit of this Company deposits by whomsoever made of
                      funds in whatever form and in whatever manner endorsed.
                      Each Fund is further authorized and directed to pay or
                      otherwise honor or apply, without inquiry and without
                      regard to the application of the proceeds thereof, checks,
                      telephone or wire instructions by an authorized officer of
                      the Company for redemptions of shares held in the
                      Company's account with such Fund, requesting that payment
                      of the redemption proceeds be made to a bank account
                      identified in the application form filed with respect to
                      opening such account and other orders for the redemption
                      of shares from such account including those drawn to the
                      individual order of a signer, when signed or otherwise
                      authorized by any one of the Chief Executive Officer, the
                      Chief Financial Officer or the Treasurer.

FURTHER

RESOLVED:             That each of the Chief Executive Officer, the Chief
                      Financial Officer or the Treasurer, acting singly be and
                      hereby is authorized and empowered, on behalf: of the
                      Company (i) to designate and empower, from time to time,
                      either by name or by title, those other officers and
                      employees of the Company who shall have such authority to
                      draw and sign checks, drafts, instruments and other order
                      upon or with respect to such funds, securities or other
                      property of the Company on deposit in any Financial
                      Institution or Fund, either individually or jointly, as
                      the Chief Executive Officer, the Chief Financial Officer
                      or the Treasurer shall prescribe provided that such

                                     - 32 -
<PAGE>

                      designation, if for amounts over $10,000 shall be made by
                      any two such officers and for amounts over $100,000, the
                      Chief Executive Officer's approval shall be obtained, and
                      (ii) to impose from time to time, such limitations and
                      conditions upon the signing authority of any such other
                      officers or employees, as the Chief Executive Officer, a
                      Vice President or the Treasurer in such officers
                      discretion shall be advisable,, provided that any
                      instructions for wire transfers of the Company's funds to
                      any third party shall require the approval of the Chief
                      Executive Officer.

FURTHER

RESOLVED:             That this Board of Directors hereby adopts the form of any
                      votes or resolutions required by any Financial Institution
                      or Fund to be filed in connection with the opening and
                      maintaining of accounts if (i) in the opinion of the Chief
                      Executive Officer, the Chief Financial Officer or the
                      Treasurer executing the same, the adoption of such votes
                      or resolutions is necessary or desirable, and (ii) the
                      Secretary or any Assistant Secretary evidences such
                      adoption by inserting In the minutes of this meeting
                      copies of such votes or resolutions, which will thereupon
                      be deemed to be adopted by this Board of Directors with
                      the same force and effect as if presented at this meeting.

FURTHER

RESOLVED:             That all designations of Financial Institutions of the
                      Company and any Fund of the Company heretofore given are
                      hereby in all respects ratified and confirmed and shall
                      continue in effect until terminated or revoked pursuant to
                      the foregoing resolutions.

FURTHER

RESOLVED:             That the Secretary or any Assistant Secretary of the
                      Company, each acting singly, be and hereby is authorized
                      and empowered to certify in a signed, written instrument
                      delivered to any Financial Institution of the Company or
                      any Fund of the Company, now or hereafter designated: (i)
                      a copy of the foregoing resolutions, (ii) the names of the
                      persons and/or of the corporate offices, who or which,
                      from time to Vine, may have signing power granted pursuant
                      to such resolutions or heretofore granted by this Board of
                      Directors, upon any account of the Company at such
                      Financial Institution or any money market funds account of
                      the Company at such Fund, and (iii) a specimen of the
                      manual signature of each person who may have signing
                      authority upon any account of the Company at any Financial
                      Institution or Fund; each such Financial Institution and
                      Fund is hereby authorized to rely upon the said
                      certificates or notifications signed by the Secretary or
                      any Assistant Secretary unless and until the same is
                      revoked or modified by a similar certificate or
                      notification in wilting so signed and delivered to it.

                                     - 33 -
<PAGE>

FURTHER

RESOLVED:             That the Secretary or any Assistant Secretary of the
                      Company, each acting singly, be and hereby is authorized
                      and directed to certify in a signed, written instrument
                      delivered to any Financial Institution or Fund of the
                      Company now or hereafter designated: (i) as to the truth,
                      accuracy. and completeness, of the foregoing resolutions,
                      (ii) that the provisions hereof are in conformity with the
                      charter and by-laws of the Company and (iii) that the
                      foregoing resolutions arid the authority thereby conferred
                      shall remain in full force and effect until the Company
                      officially notifies said Financial Institution or Fund to
                      the contrary in writing and said Financial Institution or
                      Fund may conclusively presume that such resolutions are in
                      effect and that the persons identified from time to time
                      as officers of the Company by certificate of the Secretary
                      or any Assistant Secretary have been duly elected or
                      appointed to and continue to hold such offices.

FURTHER

RESOLVED:             That any person authorized hereby to establish and
                      maintain accounts on behalf of the Company will not, and
                      will not permit any other person to, take any action which
                      would result in the Company becoming an "investment
                      company" or an "affiliated company" or a "principal
                      underwriter" of an "investment company," as such terms are
                      defined in the Investment Company Act of 1940.

FURTHER

RESOLVED:             That all investments made on behalf of the Company shall
                      be made in accordance with the investment policy presented
                      to the directors at this meeting.

                                     - 34 -

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