<PAGE>   1

                                                                   EXHIBIT 10.13

                               LICENSE AGREEMENT

     This Agreement, made and entered into as of this 29th day of June 1995
(the "Effective Date") by and between THE JOHNS HOPKINS UNIVERSITY, a
corporation duly organized and existing under the laws of the State of Maryland
and having its principal place of business at Charles and 34th Streets,
Baltimore, Maryland 21218, U.S.A. (hereinafter referred to as "JOHNS HOPKINS")
and SANGAMO BIOSCIENCES, INC. a corporation duly organized under the laws of
Delaware and having its principal office at P.O. Box 334, Ross, California
94957 (hereinafter referred to as "LICENSEE").

                                   WITNESSETH

     WHEREAS, JOHNS HOPKINS is the owner of certain Patent Rights (as later
defined herein) relating to inventions from its laboratories directed by
               *                 concerning *******************************
***************************************************************************
*************************************************** and has the right to grant
licenses under said Patent Rights, subject only to certain march-in-rights
retained by the United States Government, including royalty-free, nonexclusive
licenses;

     WHEREAS, JOHNS HOPKINS desires to have the Patent Rights utilized in the
public interest and is willing to grant a license thereunder;

     WHEREAS, JOHNS HOPKINS and LICENSEE are parties to a Research Agreement
having even date herewith (Appendix D);

     WHEREAS, JOHNS HOPKINS is acting herein for itself;

     WHEREAS, LICENSEE has represented JOHNS HOPKINS to induce JOHNS

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HOPKINS to enter into this Agreement that LICENSEE shall commit itself to a
thorough, vigorous and diligent program of exploiting the Patent Rights so that
public utilization shall result therefrom;

     WHEREAS,         *          will continue to have full academic freedom to
continue his scientific investigations and interactions with his colleagues; and

     WHEREAS, LICENSEE desires to obtain a license under the Patent Rights upon
the terms and conditions hereinafter set forth.

     NOW, THEREFORE, in consideration of the premises and the mutual covenants
contained herein, the parties hereto agree as follows:

                            ARTICLE I - DEFINITIONS

     For the purposes of this Agreement, in addition to other terms defined
herein, the following words and phrases shall have the following meanings:

     1.1  "LICENSEE" shall mean SANGAMO BIOSCIENCES and any Subsidiary of
SANGAMO BIOSCIENCES.

     1.2  "Subsidiary" shall mean any corporation, company or other entity more
than fifty percent (50%) of whose voting stock is owned or controlled directly
or indirectly by SANGAMO BIOSCIENCES; any parent corporation, company or other
entity which owns, directly or indirectly, more than fifty percent (50%) of the
voting stock of SANGAMO BIOSCIENCES; and any corporation, company or other
entity in which such parent corporation, company or other entity owns, directly
or indirectly, more than fifty percent (50%) of the voting stock.

     1.3  "Patent Rights" shall mean the inventions disclosed and claimed in
the United States and foreign patents and/or patent applications listed in
Appendix A.


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     1.4  A "Licensed Product" shall mean any product or part thereof which:

          (a)  is covered in whole or in part by an issued, valid, enforceable,
               unexpired claim or a pending claim contained in the Patent Rights
               in the country in which any Licensed Product is made, used or
               sold;

          (b)  is manufactured by using a process which is covered in whole or
               in part by a valid, enforceable, issued, unexpired claim or a
               pending claim contained in the Patent Rights in the country in
               which any Licensed Process is used or in which the Licensed
               Product is used or sold.

     1.5  A "Licensed Process" shall mean any process which is covered in whole
or in part by a valid, enforceable, issued, unexpired claim or a pending claim
contained in the Patent Rights.

     1.6  "Net Sales" shall mean the invoiced sales price of Licensed Products
to an end-user that is not a Subsidiary or a sublicensee in a country in which
such sales would infringe a valid claim contained in the Patent Rights in such
country after deducting:

          (a)  Discounts allowed in amounts customary in the trade;

          (b)  Sales taxes, tariffs, duties, use taxes and/or other
               governmental levies directly imposed and with reference to
               particular sales;

          (c)  Outbound transportation prepaid or allowed; and

          (d)  Amounts allowed or credited on returns.

No deductions shall be made for commissions paid to individuals whether they be
with independent sales agencies or regularly employed by LICENSEE and on its
payroll, or for cost of collections. Licensed Products shall be considered
"sold" when billed out or invoiced.

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     1.7  "Invention" shall mean custom designed novel DNA-binding proteins.

                               ARTICLE II - GRANT

     2.1  JOHNS HOPKINS hereby grants to LICENSEE the          *          right
and license to                 *                    the Licensed Products, and
to practice the Licensed Processes,                    *
subject to 35USC200-211 and the regulations promulgated thereunder, to the end
of the term for which the Patent Rights are granted by the applicable
governmental authority, unless sooner terminated as hereinafter provided (the
"Term"). JOHNS HOPKINS reserves the non-transferable royalty-free right to
practice the subject matter of any claim within the Patent Rights for its own
internal purposes. If         *          leaves JOHNS HOPKINS, he shall have
the non-transferable, royalty-free right to practice any claim within the
Patent Rights for his own academic purposes.

     2.2  In order to establish a period of exclusivity for LICENSEE, JOHNS
HOPKINS hereby agrees that it shall not grant any other license to     *
            *            Licensed Products or to    *     Licensed Processes
except for its internal research activities during the period of time (the
"Exclusive Period") commencing with the Effective Date of this Agreement and
terminating with expiration of the last-to-expire patent licensed under this
Agreement, unless converted earlier to a nonexclusive license pursuant to
Paragraph 4.4 hereof or pursuant to a requirement by the United States
Government in accordance with 35USC200-211.

     2.3  LICENSEE shall have the right to      *     all or any part of this
license. LICENSEE agrees that any      *      granted by it shall provide that
the obligations to JOHNS HOPKINS of Articles II, VIII, IX, X, XIII, XV, and
Paragraphs 5.1 and 5.2 of this


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Agreement shall be binding upon the      *       as if it were a party to this
Agreement. LICENSEE further agrees to attach copies of these Articles to
    *      agreements.

     2.4  LICENSEE agrees to forward to JOHNS HOPKINS a copy of any and all
fully executed     *      agreements, and further agrees to forward to JOHNS
HOPKINS, quarterly, pursuant to Paragraph 5.2 a copy of such reports received
by LICENSEE from its      *       during the preceding twelve (12) month period
under the      *      as shall be pertinent to a royalty accounting under said
    *      agreements.

     2.5  Subject to Sections 2.6, 2.7 and 15.7 below, the license granted
hereunder shall not be construed to confer any rights upon LICENSEE by
implication, estoppel or otherwise as to any technology not specifically set
forth in Appendix A, Appendix B, Appendix C, and Appendix D hereof.

     2.6  JOHNS HOPKINS hereby also grants to LICENSEE a right of first
negotiation at then commercially reasonable terms, to obtain an exclusive
license to any Inventions, as previously defined, developed during the term of
this Agreement and any extension thereof and pursuant to any Research Agreement
between the parties hereto (Appendix D). JOHNS HOPKINS shall promptly give
LICENSEE written notice of any such Inventions, as defined, and LICENSEE shall
have one hundred and twenty (120) days from the date of receipt of such notice
to give JOHNS HOPKINS written notice of its intent to exercise such option and
complete negotiations. JOHNS HOPKINS shall not negotiate with any third party
regarding these Inventions during the period of LICENSEE's right to negotiate.
During the term of this Agreement and any extension thereof,         *
shall be free to pursue any scientific investigations of his choice through
collaboration with colleagues. Should any such collaboration involve a Licensed
Product or Licensed Process, JOHNS HOPKINS will take the initiative of promptly
communicating


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with these colleagues for the purpose of using its reasonable best efforts to
have such colleagues agree to be bound by the terms of this Agreement with
regard to Licensed Products and Licensed Processes.

     2.7  Appendix B attached hereto contains ideas conceived by
      *        for developing ***********************************
*****************************************************************.
      *        shall give written notice of any Invention resulting under the
Advanced Technology Program within sixty (60) days of the completion of the
funding of such program. Any Invention resulting in whole or in part from said
ideas which are made pursuant to an award under the Advanced Technology Program
where a grant application was filed on March 29, 1995 (Appendix C) shall be
assigned to LICENSEE pursuant to Section 15.7 below and          *         will
be named as sole inventor unless another individual makes a creative input to
said Invention. LICENSEE shall have the first right of negotiation, under then
commercially reasonable terms, to obtain an exclusive, royalty-bearing license
under any Invention resulting from said ideas in Appendix B made by
      *        with funding from a source other than the Advanced Technology
Program grant.

                          ARTICLE III - DUE DILIGENCE

     3.1  In order to assure the diligent development of the Licensed Products
and Licensed Processes, LICENSEE shall either fulfill the due diligence
milestones set forth in Paragraph 3.2 below or make the minimum royalty
payments set forth in Paragraph 3.3 below.

     3.2  LICENSEE's due diligence milestones shall be a follows:

          (a)  Within six (6) months from the date of this Agreement, LICENSEE
               shall deliver a business plan describing a program for the
               development of the Patent Rights.


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          (b)  Within four (4) years from the Effective Date of this Agreement,
               LICENSEE shall have spent or caused to be spent, either directly
               by LICENSEE or indirectly pursuant to agreements entered into by
               LICENSEE (including Research Agreement funding and grant funding
               provided by or associated with LICENSEE to JOHNS HOPKINS), a
               total of One Million Dollars ($1,000,000) on activities relating
               to the                           *
                             of Licensed Products and Licensed Processes. All
               amounts expended on Licensed Products and Licensed Processes
               shall be credited toward the above indicated amounts, including
               but not limited to salaries, overhead salaries, overhead,
               capital, equipment, consulting fees and cost of materials.

          (c)  Within four (4) years from the Effective Date of this Agreement,
               LICENSEE shall submit an Experimental Plan for, and begin
               experimental work on, an appropriate testing program for at least
               one (1) Licensed Product. Such Experimental Plan shall be
               sufficiently detailed and comprehensive that, in the good faith
               opinion of LICENSEE and its counselors, the Plan shall, if
               successful, be reasonably adequate to support a credible and
               potentially successful Investigative New Drug (IND) application
               to the U.S. Food and Drug Administration within seven (7) years
               from the Effective Date of this Agreement.

          (d)  Within seven (7) years of the Effective Date of this Agreement,
               LICENSEE shall have submitted a complete Investigative New Drug
               application to the U.S. FDA, such IND to be supported with
               appropriate studies and other toxicity and safety tests as may be
               required by the FDA.

          (e)  Within three (3) years of the Effective Date of this Agreement,
               LICENSEE shall have made a first commercial sale of at least one
               (1) Licensed Product.

     3.3  In the event that LICENSEE has failed to meet any particular due
diligence milestone set forth in Paragraph 3.2 above on or before the date set
forth therein with respect to each such milestone, JOHNS HOPKINS shall notify
LICENSEE thereof and LICENSEE shall have ninety (90) days following such
notification either to establish to the

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reasonable satisfaction of JOHNS HOPKINS that it has met such milestone or to
make the initial penalty payment referred to in Paragraph 3.4 below.

     3.4  In the event that LICENSEE shall have failed to establish its
achievement of any particular milestone to the reasonable satisfaction of JOHNS
HOPKINS as set forth in Paragraph 3.3 above, JOHNS HOPKINS shall have the right
to terminate this Agreement, unless LICENSEE shall make to JOHNS HOPKINS the
following penalty payments:

          (a)  To maintain the exclusive rights granted herein on an exclusive
               basis as set forth in Paragraph 2.2, the amount of      *
                                 in the year of the breach and       *
                                 annually thereafter until the breach is cured;
               with such amount increasing to               *
                          annually commencing the eighth year following the
               Effective Date of this Agreement.

          (b)  To maintain its rights granted herein without the exclusivity
               provisions of Paragraph 2.2, the sum of          *
                                 in the year of the breach and       *
                                          per year thereafter until cured.

     The penalty payments described in (a) and (b) above shall only be due
within thirty (30) days following the failure of LICENSEE to achieve a
milestone or cure such failure within the ninety (90) days set forth in
Paragraph 3.3 above. LICENSEE's obligation to make such penalty payments shall
terminate when the applicable milestone has been met.

                             ARTICLE IV - ROYALTIES

     4.1  For the rights, privileges and license granted hereunder, LICENSEE
shall pay to JOHNS HOPKINS in the manner hereinafter provided for so long as
LICENSEE by its activities would, but for the licenses granted herein, infringe
a valid, enforceable claim of an unexpired Patent Right or until this Agreement
shall be terminated as hereinafter

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provided:

          (a)  At the time that LICENSEE closes financing equal to a total
               cumulative equity investment of at least Five Hundred Thousand
               Dollars ($500,000) ("Initial Financing"), LICENSEE shall issue to
               JOHNS HOPKINS that number of common units equal to that portion
               of the total number of common and preferred units issued with
               respect to the first                      *                   in
               equity capital invested in the LICENSEE multiplied by   *  . If
               the preferred units issued in any financing have antidilution
               protection, JOHNS HOPKINS shall be entitled to equivalent
               protection for its common units. JOHNS HOPKINS shall also be
               entitled, at its sole option, to invest its own funds in the
               second and any subsequent round of investment funding at a price
               per unit which is the same price as is offered to other second
               round investors, for up to a total number of shares such that
               JOHNS HOPKINS' share of equity in the Company would remain at
                              *                 .

          (b)  At the time that the cumulative equity capital invested in the
               Company is equal to Two Million Dollars ($2,000,000), LICENSEE
               shall pay to JOHNS HOPKINS:

               (i)  a License Issue Fee of                *
                                  *                 of said License Issue Fee
                    shall be considered an Administrative Signing Fee); and

               (ii) shall commence annual maintenance fees of        *
                            *        due on January 1 of each year following the
                    financing date.

          (c)  LICENSEE shall also pay to JOHNS HOPKINS a running royalty on
               Licensed Products during the Exclusive Period for such products
               as follows:

               (i)  For sales by LICENSEE and it Subsidiaries:

                    (1)  for ******* ********,               *
                                    *          of Net Sales;        *
                                              *               of Net Sales; and
                                                 *


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                             *     ;

                    (2)  for ********** ********,        *        of Net Sales;
                              *        of Net Sales; and        *
                              *   of Net Sales in excess of    *
                              *   ; and

                    (3)  for *********** ********,           *
                            *  of Net Sales;       *     of Net Sales; and
                            *  of Net Sales in excess of     *
                            *  .

               (ii) for sales by   *  :

                    (1)  for ******** *******, the greater of  *  of Net Sales
                         or       *            royalties received by LICENSEE;

                    (2)  for ********** ********, the greater of  *   of Net
                         Sales or    *        of          *        royalties
                         received by LICENSEE; and

                    (3)  for ********** ********, the greater of    *    of Net
                         Sales or       *       of      *     royalties
                         received by LICENSEE.

          (d)  LICENSEE shall pay to JOHNS HOPKINS  *  of initial License Fees
               (excluding all other forms of payment including, but not limited
               to, research funding) LICENSEE receives from all   *     .

          (e)  During the nonexclusive period for any Licensed Product,
               LICENSEE shall pay to JOHNS HOPKINS a running royalty on the Net
               Sales of such Licensed Products sold by LICENSEE, its
               Subsidiaries and its     *          equal to    *       the
               royalty set forth in (c) above for sales during the Exclusive
               Period.

     4.2  No multiple royalties shall be payable because any Licensed Product,
its

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               *           are or shall be covered by more than one patent
application or patent licensed under this Agreement or acquired under a license
pursuant to Paragraph 2.6 or 2.7. If a Licensed Product is covered by this
Agreement and a License Agreement pursuant to Paragraph 2.6 and/or 2.7 the
highest applicable royalty rate will apply. If, as to any Licensed Product,
LICENSEE is required to pay a royalty to any third party, the royalty rates set
forth in Paragraph 4.1 shall be reduced by        *       of the royalty rates
paid to the third party, but in no event shall the rates in Paragraph 4.1 be
reduced by more than          *         .

     4.3  Royalty payments shall be paid in United States dollars in Baltimore,
Maryland, at the time and in the manner provided in Article V below. If any
currency conversion shall be required in connection with the payment of
royalties hereunder, such conversion shall be made by using the exchange rate
prevailing at the Bank of America Corporation on the last business day of the
calendar quarterly reporting period to which such royalty payments relate.

     4.4  At the end of the first calendar year beginning after the first
commercial sale of a Licensed Product by LICENSEE, a subsidiary, or a
     *     , and each calendar year thereafter (hereinafter "Royalty Year"),
LICENSEE shall pay JOHNS HOPKINS the greater of royalties payable pursuant to
Paragraph 4.1(c) or a minimum annual royalty according to the following
schedule:

  At the End of the First Royalty Year  -               *

  At the End of the Second Royalty Year -               *

  At the End of the Third and Through
  the Ninth Royalty Year                -               *

  At the End of the Tenth and Each
  Subsequent Royalty Years              -               *


Said minimum annual royalty shall be paid to JOHNS HOPKINS within thirty (30)
days of

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the end of each Royalty Year. Failure by LICENSEE to pay the minimum annual
royalty required by this Paragraph 4.4 shall give JOHNS HOPKINS the right to
convert the     *     license granted by this Agreement to       *
license.

                        ARTICLE V - REPORTS AND RECORDS

     5.1  LICENSEE shall keep full, true and accurate books of account
containing all particulars that may be necessary for the purpose of showing the
amounts payable to JOHNS HOPKINS hereunder. Said books of account shall be kept
at LICENSEE's principal place of business or the principal place of business of
the appropriate Division of LICENSEE to which this Agreement relates. Said
books and the supporting data shall be open at all reasonable times for five
(5) years following the end of the calendar year to which they pertain, to the
inspection of JOHNS HOPKINS or its agents for the purpose of verifying
LICENSEE's royalty statement or compliance in other respects with this
Agreement.

     5.2  Commencing with the first commercial sale of a Licensed Product,
LICENSEE, within sixty (60) days after March 31, June 30, September 30 and
December 31, of each year, shall deliver to JOHNS HOPKINS true and accurate
reports, giving such particulars of the business conducted by LICENSEE, its
Subsidiaries and its sublicensees during the preceding three-month period under
this Agreement as shall be pertinent to a royalty accounting hereunder. These
shall include at least the following:

          (a)  All Licensed Products manufactured and sold.

          (b)  Total billings for Licensed Products sold.

          (c)  Accounting for all Licensed Processes used or sold.


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               (d)  Deductions applicable as provided in Paragraph 1.6.

               (e)  Total royalties due.

               (f)  Names and addresses of all sublicensees of LICENSEE.

Where reasonably practical, LICENSEE shall, to the best of its knowledge,
subcategorize the Licensed Products sold so as to assign the royalties paid to
individual patent(s) of Appendix A. Such subcategorization shall be for JOHNS
HOPKINS administrative purposes only and shall in no way affect any obligations
of any part or the amounts of royalties to be paid under this Agreement. Until
there has been a first commercial sale of a Licensed Product, the LICENSEE
shall give an annual report of LICENSEE's efforts to achieve a first commercial
sale.

     5.3  With each such report submitted, LICENSEE shall pay to JOHNS HOPKINS
the royalties due and payable under this Agreement. If no royalties shall be
due, LICENSEE shall so report.

     5.4  The royalty payments set forth in this Agreement shall, if overdue,
bear interest until payment at a per annum rate           *            the
prime rate in effect at Bank of America on the due date. The payment of such
interest shall not foreclose JOHNS HOPKINS from exercising any other rights it
may have as a consequence of the lateness of any payments.

                        ARTICLE VI - PATENT PROSECUTION

     6.1  JOHNS HOPKINS represents that Appendix A, as amended from
time-to-time, contains an accurate and complete listing of the patent
applications and issued patents included within the Patent Rights. JOHNS
HOPKINS agrees to promptly amend Appendix A within thirty (30) days of any new
Invention made pursuant to the ATP.


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     6.2  JOHNS HOPKINS warrants that it has the right to grant the rights and
licenses granted herein to LICENSEE free and clear of all liens and
encumbrances, except to the extent set forth in Article XII.

     6.3  Within ninety (90) days of the completion of the financing set forth
in Paragraph 4.1(b), LICENSEE shall reimburse JOHNS HOPKINS for
previously-incurred as well as future expenses paid to third parties relating
to drafting, filing, prosecuting and maintaining U.S. and foreign patent
applications and patents included in the Patent Rights; provided, however, if
such reimbursement amount exceeds Fifty Thousand Dollars ($50,000), then the
amount above $50,000 shall be due twenty-four (24) months from the date of the
initial payment, JOHNS HOPKINS shall, on LICENSEE's request and expense, file,
prosecute, and maintain appropriate additional foreign patent applications and
patents directed to the inventions which will be included in the Patent Rights
and LICENSEE shall be licensed thereunder. If LICENSEE elects not to pay
expenses associated with filing, prosecuting, and maintaining U.S. and foreign
patent applications and patents directed to the inventions, JOHNS HOPKINS may
file, prosecute, and maintain such U.S. and foreign patent applications and
patents at its own expense and LICENSEE shall not be licensed thereunder.

     6.4  With regard to substantive correspondence, patent applications and
patents included in the Patent Rights, JOHNS HOPKINS shall in a timely manner
send LICENSEE (a) copies of all proposed patent applications and correspondence
to the respective patent office, give LICENSEE an opportunity to comment
thereon, and incorporate such changes as reasonably requested by LICENSEE; and
(b) copies of correspondence from the patent office.

     6.5  JOHNS HOPKINS shall reasonably respond to LICENSEE's request for

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<PAGE>   15
change in outside patent counsel.

                           ARTICLE VII - INFRINGEMENT

     7.1  Each party to this Agreement shall promptly notify the other party in
writing of any alleged infringement and of any available evidence of
infringement by a third party of any patents within the Patent Rights of which
it becomes aware.

     7.2  During the term of this Agreement, LICENSEE shall have the right, but
shall not be obligated, to prosecute at its own expense any such infringements
of the Patent Rights and, in furtherance of such right, LICENSEE hereby agrees
that JOHNS HOPKINS may join LICENSEE as a party plaintiff in any such suit,
without expense to JOHNS HOPKINS, provided, however, that such right to bring
an infringement action shall remain in effect only for so long as the license
granted herein remains exclusive. No settlement, consent judgment or other
voluntary final disposition of the suit may be entered into without the consent
of JOHNS HOPKINS, which consent shall not unreasonably be withheld. LICENSEE
shall indemnify JOHNS HOPKINS against any order for costs or other expenses
that may be made against JOHNS HOPKINS in such proceedings. The total cost of
any such infringement action commenced or defended solely by LICENSEE shall be
borne by LICENSEE, and LICENSEE shall keep any recovery damages for past
infringement derived therefrom, after payments to JOHNS HOPKINS of the royalty
rate set forth in Paragraph 4.1(c)(i) applied to the sum of the recovery,
damages or any other amount received in any form of disputation and/or in
settlement of any infringement or alleged infringement of the Patent Rights
remaining after LICENSEE has reimbursed itself for all costs, including legal
costs, associated with the prosecution.

     7.3  If within six (6) months after having been notified of any alleged
infringement,


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<PAGE>   16
LICENSEE shall have been unsuccessful in persuading the alleged infringer to
desist and shall not have brought and shall not be diligently prosecuting any
infringement action, or if LICENSEE shall notify JOHNS HOPKINS at any time
prior thereto of its intention not to bring suit against any alleged
infringer, then, JOHNS HOPKINS shall have the right, but shall not be obligated
to prosecute at its own expense any infringement of the Patent Rights, and
JOHNS HOPKINS may, for such purposes, use the name of LICENSEE as party
plaintiff without expense to LICENSEE, and JOHNS HOPKINS shall keep any
recovery or damages derived therefrom.

     7.4  In the event that a declaratory judgment action alleging invalidity
or noninfringement of any of the Patent Rights shall be brought against
LICENSEE, JOHNS HOPKINS at its option, shall have the right, within thirty (30)
days after commencement of such action, to intervene and participate in the
defense of the action at their own expense.

     7.5  In any infringement suit that any party hereto may institute to
enforce the Patent Rights pursuant to this Agreement, the other party hereto
shall, at the request and expense of the party initiating such suit, cooperate
in all respects and, to the extent possible, have its employees testify when
requested and make available relevant records, papers, information, samples,
specimens, and the like.

     7.6  LICENSEE, during the Exclusive Period of this Agreement, shall have
the sole right in accordance with the terms and conditions herein to sublicense
any alleged infringer under the Patent Rights to avoid future infringements.
Amounts received from any such      *      constituting retroactive royalties
shall be considered amounts received in settlement and accounted for under
Paragraph 7.2 above. Otherwise, amounts received from such sublicensee shall be
treated in accordance with Paragraph


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<PAGE>   17
4.1(c) above.

                            ARTICLE VIII - LIABILITY

     8.1  Inasmuch as JOHNS HOPKINS will not, under the provisions of this
Agreement or otherwise, have control over the manner in which LICENSEE, or its
Subsidiaries or its agents or its sublicensees or those operating for its
account, or third parties who purchase Licensed Products from any of the
foregoing entities, practice any invention encompassed by the license granted
herein, LICENSEE shall defend and hold JOHNS HOPKINS, it trustees, officers,
employees, students, and affiliates harmless as against any judgments, fees,
expenses or other costs (including reasonable attorneys' fees) arising from or
incidental to any product liability or other lawsuit brought as a consequence
of the practice of said invention by any of the foregoing entities, whether or
not JOHNS HOPKINS is named as party defendant in any such lawsuit. LICENSEE
shall have the right to defend such a product liability lawsuit with counsel of
its own choosing and JOHNS HOPKINS will cooperate in the defense of such action
at LICENSEE's expense. Practice of the Invention encompassed by the license
granted herein by a Subsidiary or an agent or a      *     , or a third party
on behalf of or for the account of LICENSEE or by a third party who purchases
Licensed Products from any of the foregoing shall be considered LICENSEE's
practice of said invention for purposes of this Paragraph 8.1. The provisions
of this Paragraph 8.1 shall survive termination of this Agreement.

     8.2  LICENSEE shall maintain or cause to be maintained, prior to the first
planned use of Licensed Products or Licensed Processes in humans, product
liability insurance or other protection reasonably acceptable to JOHNS HOPKINS
which shall


                                       17


* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.

<PAGE>   18
protect LICENSEE and JOHNS HOPKINS in regard to events covered by Paragraph 8.1
above. LICENSEE will disclose to JOHNS HOPKINS the amount and kind of product
liability insurance it obtains, will give JOHNS HOPKINS a copy of the
certificate of insurance, and will increase or change the kind of insurance at
the reasonable request of JOHNS HOPKINS, provided such insurance is available
to LICENSEE at commercially reasonable rates.

     8.3  Except as otherwise expressly set forth in this Agreement, JOHNS
HOPKINS makes no representations and extend no warranties of any kind, either
express or implied, including but not limited to warranties of merchantability,
fitness for a particular purpose, and validity of Patent Rights claims, issued
or pending.

     8.4  No liability under this Agreement shall result to a party from delay
in performance caused by force majeure, that is, circumstances beyond the
reasonable control of the party affected thereby, including, without
limitation, acts of God, earthquake, fire, flood, war, government regulations,
labor unrest, or shortage of or an inability to obtain material or equipment.

                          ARTICLE IX - EXPORT CONTROLS

     It is understood that JOHNS HOPKINS is subject to United States laws and
regulations controlling the export of technical data, computer software,
laboratory prototypes and other commodities (including the Arms Export Control
Act, as amended and the Export Administration Act of 1979), and that their
obligations hereunder are contingent on compliance with applicable United
States export laws and regulations. The transfer of certain technical data and
commodities may require a license from the cognizant agency of the United
States Government and/or written assurances by

                                      -18-
<PAGE>   19
LICENSEE that LICENSEE shall not export data or commodities to certain foreign
countries without prior approval of such agency. JOHNS HOPKINS neither
represents that a license shall not be required nor that, if required, it shall
be issued.

                          ARTICLE X - NON-USE OF NAMES

     LICENSEE shall not use the name of JOHNS HOPKINS, nor any of its
employees, or any adaptation thereof, in any advertising, promotional or sales
literature without prior written consent obtained from JOHNS HOPKINS in each
case, except that LICENSEE may state that it is licensed by JOHNS HOPKINS under
one or more of the patents and/or applications comprising the Patent Rights.

                            ARTICLE XI - ASSIGNMENT

     This Agreement may not be assigned, in whole or in part, except in
conjunction with the sale of the entire business, or an operating business
division, of LICENSEE to which the Patent Rights relate, without the prior
consent of JOHNS HOPKINS, which consent shall not be unreasonably withheld.

                        ARTICLE XII - GOVERNMENT RIGHTS

     12.1 Pursuant to 35USC202, JOHNS HOPKINS has elected to take all rights,
title and interest in the inventions forming the basis of the Patent Rights.

     12.2 LICENSEE hereby specifically agrees to cooperate with JOHNS HOPKINS
in abiding by the terms and conditions imposed on JOHNS HOPKINS pursuant to
35USC200-211 and the regulations promulgated thereunder.

                                       19

<PAGE>   20
     12.3  JOHNS HOPKINS warrants that it has compiled with and will continue
to comply with all duties and obligations running from JOHNS HOPKINS to the
Government pursuant to 35USC200-211 and the regulations promulgated thereunder.

     12.4  LICENSEE agrees to      *      in the United States those Licensed
Products which are       *       in the United States.


                           ARTICLE XIII - TERMINATION

     13.1  This Agreement shall terminate if LICENSEE dissolves, unless this
Agreement has been assigned prior to the date of dissolution.

     13.2  Should LICENSEE fail to pay JOHNS HOPKINS royalties due and payable
hereunder, JOHNS HOPKINS shall have the right to terminate this Agreement on
sixty (60) days' written notice, unless LICENSEE shall pay JOHNS HOPKINS within
the sixty (60) day period, all such royalties and interest due and payable.
Upon the expiration of the sixty (60) day period, if LICENSEE shall not have
paid all such royalties and interest due and payable, the rights, privileges
and license granted hereunder shall terminate.

     13.3  Upon any material breach or default of this Agreement by LICENSEE
other than those occurrences set out in Paragraphs 13.1 and 13.2 hereinabove,
which shall always take precedence in that order over any material breach or
default referred to in this Paragraph 13.3, JOHNS HOPKINS shall have the right
to terminate this Agreement and the rights, privileges and license granted
hereunder by giving ninety (90) days' notice to LICENSEE. Such termination
shall become effective unless LICENSEE shall have cured any such breach or
default prior to the expiration of the ninety (90) day period.

     13.4  LICENSEE shall have the right to terminate this Agreement at any
time on six (6) months' notice to JOHNS HOPKINS and upon payment of all amounts
due JOHNS

                                       20

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.

<PAGE>   21
HOPKINS.

     13.5  Upon termination of this Agreement for any reason, nothing herein
shall be construed to release either party from any obligation that matured
prior to the effective date of such termination. LICENSEE and any Subsidiary
and sublicensee thereof may, however, after the effective date of such
termination,  *   all Licensed Products, and complete Licensed Products in the
process of      *      at the time of such termination and  *   the same,
provided that LICENSEE shall pay to JOHNS HOPKINS the royalties thereon as
required by Article IV of this Agreement and shall submit the reports required
by Article V hereof on the sales of Licensed Products.

     13.6  Upon termination of this Agreement for any reason during the
Exclusive Period, any      *      not then in default shall have the right to
seek a license from JOHNS HOPKINS under the same terms and conditions as set
forth hereunder.

     13.7  The provisions of Paragraph 8.1, Article IX, and Article X shall
survive termination of this Agreement.

            ARTICLE XIV - PAYMENTS, NOTICES AND OTHER COMMUNICATIONS

     Any payment, notice or other communication pursuant to this Agreement
shall be sufficiently made or given on the date of mailing if sent to such
party by certified first class mail, postage prepaid, addressed to it at its
address below or as it shall designate by written notice given to the other
party:

     In the case of JOHNS HOPKINS:

          Johns Hopkins University
          300 Whitehead Hall
          Charles and 34th Streets
          Baltimore, Maryland  21218
          Attention: Edwin T. Yates, Ph.D.


                                       21

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.
<PAGE>   22
                                    [Blank]


















                                       22
<PAGE>   23
With a copy to:

     Associate Dean for Corporate Affairs
     Johns Hopkins University
     School of Hygiene and Public Health
     111 Market Place, Suite 840
     Baltimore, Maryland  21202-6709
     Attention: Alan M. Goldberg, Ph.D.

In the case of LICENSEE:

     Edward Lanphier
     Sangamo BioSciences, Inc.
     P.O. Box 334
     Ross, California 94957

With a copy to:

     Stephan Dolezalek, Esq.
     Brobeck, Phleger & Harrison
     Two Embarcadero Place
     2200 Geng Road
     Palo Alto, California 94303


                     ARTICLE XV - MISCELLANEOUS PROVISIONS

     15.1  This Agreement shall be construed, governed, interpreted and applied
in accordance with the laws of the State of Maryland, U.S.A., except that
questions affecting the validity, construction and effect of any patent
licensed hereunder, shall be determined by the law of the country in which the
patent was granted.

     15.2  The parties hereto acknowledge that this Agreement sets forth the
entire Agreement and understanding of the parties hereto as to the subject
matter hereof, and shall not be subject to any change or modification except by
the execution of a written instrument subscribed to by the parties hereto.

                                       23

<PAGE>   24
     15.3 The provisions of this Agreement are severable, and in the event that
any provisions of this Agreement shall be determined to be invalid or
unenforceable under any controlling body of the law, such invalidity or
unenforceability shall not in any way affect the validity or enforceability of
the remaining provisions hereof.

     15.4 LICENSEE agrees to mark the Licensed Products sold in the United
States with all applicable United States patent numbers. All Licensed Products
shipped to or sold in other countries shall be marked in such a manner as to
conform with the patent laws and practice of the country of manufacture or sale.

     15.5 The failure of any party to assert a right hereunder or to insist upon
compliance with any term or condition of this Agreement shall not constitute a
waiver of that right or excuse a similar subsequent failure to perform any such
term or condition by the other party.

     15.6 Claims, disputes, or controversies concerning the validity,
construction, or effect of any patent licensed hereunder shall be resolved in
any court having jurisdiction thereof.

     15.7 A grant application under the Advanced Technology Program was filed on
March 29, 1995 (Appendix C). If a grant is awarded, any Invention made pursuant
thereto where an investigator at JOHNS HOPKINS is the sole inventor or a
coinventor shall be assigned to LICENSEE. Such Invention shall be assigned
hereunder and shall thereafter fall within the definition of Patent Rights and
therefore shall be subject to Sections 3.2, 3.3 and 3.4 hereof and to the
royalty payments required by Sections 4.1(c)(i), 4.1(d) and 4.4 hereof as part
of the rights licensed hereunder.


                                      24
<PAGE>   25
     IN WITNESS WHEREOF, the parties have hereunto set their hands and seals
and duly executed this Agreement the day and year set forth below.


JOHNS HOPKINS UNIVERSITY


By:
    -------------------------------------------------------
    Herbert R. Hansen, Jr., MBA, CPA
    Senior Associate Dean, Finance and Administration

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

                                       OR


By: /s/ Alan M. Goldberg
    -------------------------------------------------------
    Alan M. Goldberg, Ph.D.
    Associate Dean, Corporate Affairs

Date: July 10th, 1995
      ----------------------------------

                                      AND

By: /s/ John Groopman
    -------------------------------------------------------
    John Groopman, Ph.D.
    Chairman, Environmental Health Sciences

Date: 7/10/95
      ----------------------------------


SANGAMO BIOSCIENCES, INC.


By: /s/ Edward O. Lanphier II
    -------------------------------------------------------
    Edward O. Lanphier II
    President

Date: June 30, 1995
      ----------------------------------


                                       25
<PAGE>   26
                                   APPENDIX A

PATENTS:



                                   APPENDIX B

INVENTION DISCLOSURES:



                                   APPENDIX C


ADVANCED TECHNOLOGY PROGRAM GRANT PROPOSAL:




                                   APPENDIX D


RESEARCH AGREEMENT:


                                       26
<PAGE>   27
                          THE JOHNS HOPKINS UNIVERSITY
                            BALTIMORE, MD 21218-2696

Nina M. Siegler, C.F.A.                           Office of Technology Transfer
Director                                                708 N Wyman Park Center
                                                         3400 N. Charles Street
                                                                 (410) 516-8137
                                                             Fax (410) 516-7811

                                AMENDMENT NO. 1

                        TO THE LICENSE AGREEMENT between

             Johns Hopkins University and Sangamo Biosciences, Inc.


     This Amendment No. 1, dated June 1, 1998 ("Effective Date") to the License
Agreement dated June 29, 1995 concerning the licensing and other matters of
patent properties referred to in the License Agreement as

                                       *
                                                   and other Patent Rights, is
entered into between Johns Hopkins University, a not-for-profit educational
institution having an address at 3400 N. Charles Street, Baltimore, MD ("JOHNS
HOPKINS" or "JHU") and Sangamo Biosciences, Inc., a corporation of the State of
Delaware and having a principal place of business at Point Richmond Tech
Center, 501 Canal Blvd, Suite A-100, Richmond, CA ("LICENSEE").

This document amends the License Agreement by the following:

1.   In Paragraph 4.1, delete in its entirety paragraph 4.1.(c). Replace with
     new Paragraph 4.1.(c):

               4.1.(c)  LICENSEE shall also pay to JOHNS HOPKINS a running
               royalty on Licensed Products as follows:

                        (i) for therapeutic products,        *         of Net
                            Sales
                        (ii) for diagnostic products,        *         of Net
                             Sales
                        (iii) for reagent products,            *            of
                              Net Sales

2.   Delete in its entirety Paragraph 4.4, and replace with the following new
     Paragraph 4.4:

               4.4  LICENSEE shall pay to JOHNS HOPKINS a minimum annual royalty
               according to the following schedule and within thirty (30) days
               of the end of the calendar year:




* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.
<PAGE>   28
Amendment No. 1
Sangamo License Agreement
page 2

                         1999,2000         *    per year
                         2001-2005         *    per year
                         2006 and until termination    *    per year


               Failure by LICENSEE to pay the minimum annual royalty required by
               this Paragraph 4.4 shall give JOHNS HOPKINS the right to convert
               the exclusive license granted by this Agreement to a nonexclusive
               license.

3.   Add new Paragraph 4.5 as follows:

               4.5  For the rights, privileges and license granted by Amendment
               No. 1, dated ______, LICENSEE agrees to pay to JOHNS HOPKINS the
               sum of                      *                            ,
               payable in equal installments within eighteen months of the
               Effective Date of Amendment No. 1.

4.   Add new Paragraph 6.6 as follows:

               6.6  LICENSEE shall have the right, but not the obligation, to
               assume primary responsibility for patent prosecution. JOHNS
               HOPKINS hereby agrees to reasonably cooperate with the transfer
               of case files, execution of appropriate documents and any other
               matters needed for LICENSEE to assume such responsibility. In
               such case, LICENSEE shall provide to JHU copies of all
               correspondence from and to the US PTO and international
               equivalents with sufficient time to allow for comment by JHU.
               LICENSEE shall endeavor to accommodate JHU's comments into a
               reasonable patent prosecution strategy. In no case shall LICENSEE
               abandon any application or patent in any country without prior
               approval from JHU. In any country where the LICENSEE elects not
               to have a patent application filed or to pay expenses associated
               with filing, prosecuting, or maintaining a patent application or
               patent, LICENSEE shall notify JHU allowing at least thirty (30)
               days for JHU to assume such responsibilities. JHU may file,
               prosecute, and/or maintain a patent application or patent at its
               own expense and for its own exclusive benefit and the LICENSEE
               thereafter shall not be licensed under such patent or patent
               application. Upon termination of this Agreement, LICENSEE shall
               immediately transfer all case files, execute any appropriate
               documents related to patent matters and cooperate in any other
               matters needed for JHU to assume responsibility for patent
               prosecution.


                                       2

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.
<PAGE>   29
Amendment No. 1
Sangamo License Agreement
page 3

5.   In Paragraph 13.7, add after "Article X", insert, "Paragraph 4.5 and
Paragraph 6.6".

6.   Add new Paragraph 15.8 as follows:

               15.8   With respect to                  *


                                                , LICENSEE hereby acknowledges
               and agrees that         *          is the sole inventor of this
               property.

7.   In Appendix A, add:

                                          *





                                          *





8.   Except as expressly modified by this Amendment No. 1, the License Agreement
     shall remain in full force and effect.

9.   In Paragraph 3.2(e) change it to read, "Within seven (7) years of the
     Effective Date of this Agreement, LICENSEE shall have made a commercial
     sale of at least one (1) Licensed Product."


                                       3

* Certain information on this page has been omitted and filed separately with
  the Commission. Confidential treatment has been requested with respect to the
  omitted portions.
<PAGE>   30
Amendment No. 1
Sangamo License Agreement
page 4


     IN WITNESS WHEREOF, the parties have caused this Amendment to be duly
executed and delivered as of the date first written above.


For Sangamo Biosciences, Inc.:


/s/ Edward O. Lanphier II                             7/16/98
--------------------------------------            ---------------
Edward O. Lanphier II                                  Date
President


For Johns Hopkins University:



/s/ Herbert R. Hansen, J.                             7/8/98
--------------------------------------            ---------------
Herbert R. Hansen, J., MBA, CPA                        Date
Senior Associate Dean, Finance and
Administration



Sangamo Amendment #1 (6/29/98)





                                       4