Document:

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                                                                    Exhibit 4.11

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE BEEN ACQUIRED FOR INVESTMENT
AND HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED. THE
SECURITIES MAY NOT BE SOLD OR TRANSFERRED IN THE ABSENCE OF REGISTRATION OR AN
EXEMPTION THEREFROM. THE SECURITIES REPRESENTED BY THIS CERTIFICATE AND THE
RIGHTS OF THE HOLDER HEREOF ARE SUBJECT TO CERTAIN RESTRICTIONS ON TRANSFER AND
OTHER RESTRICTIONS, AND THE HOLDER OF THE SECURITIES REPRESENTED BY THIS
CERTIFICATE (INCLUDING ANY FUTURE HOLDER) IS BOUND BY THE TERMS OF A WARRANT
PURCHASE AGREEMENT BETWEEN THE ORIGINAL PURCHASER AND THE COMPANY (COPIES OF
WHICH MAY BE OBTAINED FROM THE COMPANY).

             WARRANT TO PURCHASE 1,491,544 SHARES OF COMMON STOCK OF
                                   HYSEQ, INC.

      This certifies that the holder hereof (the "Holder"), for value received,
is entitled to purchase from Hyseq, Inc., a Nevada corporation (the "Company"),
One Million, Four Hundred Ninety One Thousand, Five Hundred and Forty Four
(1,491,544) fully paid and nonassessable shares (the "Warrant Shares") of the
Company's common stock, par value $0.001 per share (the "Common Stock"), at a
price of $8.29 per share (the "Stock Purchase Price") (pursuant to that certain
Warrant Purchase Agreement between the Company and Purchaser, dated as of
January 8, 2002 (the "Warrant Purchase Agreement") at any time on or after the
date hereof, up to and including 5:00 p.m. (California time) on the Expiration
Date (as defined below), upon (a) surrender to the Company at its principal
offices at 675 Almanor Avenue, Sunnyvale, California 94085 (or at such other
location as the Company may advise the Holder in writing) of this Warrant
properly endorsed with the Notice of Conversion attached hereto duly completed
and signed, and (b) payment of the aggregate Stock Purchase Price for the
Warrant Shares. The Stock Purchase Price and the number of shares purchasable
hereunder are subject to adjustment as provided in Section 3 of this Warrant.
"Expiration Date" shall mean January 8, 2009 (or, in the event that January 8,
2009 is not a business day, the next succeeding business day).

      This Warrant may be exercised as a whole or may be exercised in part or
from time to time.

      This Warrant is issued pursuant to, and subject of the provisions of, the
Warrant Purchase Agreement and, by its acceptance of this Warrant, the Holder
expressly agrees to comply with the provisions of the Warrant Purchase Agreement
applicable to this Warrant (including, without limitation, the provisions
contained in Section 7.3 relating to subsequent transfers of this Warrant).
Terms used but not defined in this Warrant shall have the respective meanings
assigned to them in the Warrant Purchase Agreement, to which reference is hereby
made.

                                   Exhibit 4-1
<PAGE>

      This Warrant is subject to the following further terms and conditions:

      1.    EXERCISE.

            Exercise Procedure; Issuance of Certificates; Payment for Shares.
This Warrant is exercisable at the option of the Holder at any time on or after
the date hereof and prior to or on the Expiration Date for the Warrant Shares
which may be purchased hereunder. The Company agrees that the Warrant Shares
purchased under this Warrant shall be and are deemed to be issued to the Holder
as the record owner of such shares as of the close of business on the date on
which this Warrant shall have been surrendered and payment made for such shares.
Subject to the provisions of Section 2 hereof, certificates for the Warrant
Shares so purchased, together with any other securities or property to which the
Holder is entitled upon such exercise, shall be delivered to the Holder by the
Company's transfer agent at the Company's expense within a reasonable time after
the rights represented by this Warrant have been exercised. Each stock
certificate so delivered shall be in such denominations of Warrant Shares as may
be requested by the Holder and shall be registered in the name of the Holder.

            The Holder further agrees to comply with the provisions of Section
7.5 of the Warrant Purchase Agreement respecting any proposed exercise of this
Warrant.

            If the Warrant shall be converted for less than the total number of
shares of Warrant Shares then issuable upon conversion, promptly after surrender
of the Warrant upon such conversion, the Company will execute and deliver a new
warrant, dated the date hereof, evidencing the right of the Holder to the
balance of the Warrant Shares purchasable hereunder upon the same terms and
conditions set forth herein. If this Warrant is converted, as a whole or in
part, after the occurrence of an event as to which Section 3.12 is applicable,
the Holder shall receive the consideration contemplated by Section 3.12 in lieu
of Common Stock of the Company.

      2.    SHARES TO BE FULLY PAID; RESERVATION OF SHARES.

            The Company covenants and agrees that all Warrant Shares which may
be issued upon the exercise of this Warrant will, upon issuance, be validly
issued, fully paid and nonassessable and free from all preemptive or any similar
rights of any stockholder of the Company and free of any liens or encumbrances
arising through the Company, other than restrictions of transfer under the
Warrant Purchase Agreement, this Warrant and applicable state and federal
securities laws. The Company further covenants and agrees that during the period
within which this Warrant may be exercised the Company will at all times have
authorized and reserved, for the purpose of issue or transfer upon exercise of
this Warrant, a sufficient number of authorized but unissued shares of Common
Stock, when and as required to provide for the exercise of the rights
represented by this Warrant. The Company will take all such action as may be
necessary to assure that such shares of Common Stock may be issued as provided
herein without violation of any applicable law or regulation, or of any
requirements of any domestic securities exchange or automated quotation system
upon which the Common Stock is listed.

                                   Exhibit 4-2
<PAGE>

      3.    ADJUSTMENT OF STOCK PURCHASE PRICE AND NUMBER OF WARRANT SHARES
            ISSUABLE.

            The Stock Purchase Price and the number of Warrant Shares issuable
upon the exercise of each Warrant are subject to adjustment from time to time
upon the occurrence of the events enumerated in this Section 3.

            3.1 Adjustment for Change in Capital Stock. If the Company: (i) pays
a dividend or makes a distribution on its Common Stock in shares of its Common
Stock; (ii) subdivides its outstanding shares of Common Stock into a greater
number of shares; or (iii) combines its outstanding shares of Common Stock into
a smaller number of shares; then the Stock Purchase Price in effect immediately
prior to such action shall then be adjusted in accordance with the formula:

                          O
            E(1)  =  E x --
                          A

where:

            E(1)  =  the adjusted Stock Purchase Price.

            E  =  the current Stock Purchase Price.

            O  =  the number of shares of Common Stock outstanding prior to such
                  action.

            A  =  the number of shares of Common Stock outstanding immediately
                  after such action.

                  (a) In the case of a dividend or distribution the adjustment
shall become effective immediately after the record date for determination of
holders of shares of Common Stock entitled to receive such dividend or
distribution, and in the case of a subdivision or combination, the adjustment
shall become effective immediately after the effective date of such corporate
action.

                  (b) If after an adjustment the Holder of the Warrant upon
exercise of it may receive shares of two or more classes of capital stock of the
Company, the Company shall determine the allocation of the adjusted Stock
Purchase Price between the classes of capital stock. After such allocation, the
exercise privilege, the number of shares issuable upon such exercise, and the
Stock Purchase Price of each class of capital stock shall thereafter be subject
to adjustment on terms comparable to those applicable to Common Stock in this
Section 3.

                  (c) Such adjustment shall be made successively whenever any
event listed above shall occur.

      3.2 Adjustment for Rights Issue. If the Company distributes any rights,
options or warrants to all holders of its Common Stock entitling them at any
time after the record

                                   Exhibit 4-3
<PAGE>

date mentioned below to purchase shares of Common Stock at a price per share
less than the Current Market Price (as defined in Section 3.6) per share of
Common Stock on that record date, the Stock Purchase Price shall be adjusted in
accordance with the formula:

                                  N x P
                            O +  ------
                                    M

            E(1)  =  E x   ------------
                                  O + N

where:

            E(1)  =  the adjusted Stock Purchase Price.

            E  =  the current Stock Purchase Price.

            O  =  the number of shares of Common Stock outstanding on the record
                  date.

            N  =  the number of additional shares of Common Stock issuable upon
                  exercise of the rights, options or warrants offered.

            P  =  the exercise price per share of the additional shares issuable
                  upon exercise of the rights, options or warrants.

            M  =  the Current Market Price per share of Common Stock on the
                  record date.

The adjustment shall be made successively whenever any such rights, options or
warrants are issued and shall become effective immediately after the record date
for the determination of stockholders entitled to receive the rights, options or
warrants. If at the end of the period during which such rights, options or
warrants are exercisable, not all rights, options or warrants shall have been
exercised, the Stock Purchase Price shall be immediately readjusted to what it
would have been if "N" in the above formula had been the number of shares
actually issued.

            3.3 Adjustment for Other Distributions. If the Company distributes
to all holders of its Common Stock any of its assets (including but not limited
to securities and cash), debt securities, capital stock, or any rights or
warrants to purchase assets, debt securities, capital stock, or other securities
of the Company, the Stock Purchase Price shall be adjusted in accordance with
the formula:

                            M - F
            E(1)  =  E  x  ------
                            M

where:

            E(1)  =  the adjusted Stock Purchase Price.

                             Exhibit 4-4
<PAGE>

            E  =  the current Stock Purchase Price.

            M  =  the Current Market Price per share of Common Stock on the
                  record date mentioned below.

            F  =  the fair market value on the record date of the assets, debt
                  securities, capital stock or rights or warrants applicable to
                  one share of Common Stock. The Board of Directors shall
                  determine the fair market value.

The adjustment shall be made successively whenever any such distribution is made
and shall become effective immediately after the record date for the
determination of stockholders entitled to receive the distribution.

      This subsection does not apply to (i) dividends, distributions,
combinations or issuances referred to in subsection 3.1, (ii) rights, options or
warrants referred to in subsection 3.2, or (iii) non-extraordinary quarterly
cash dividends distributed to all holders of Common Stock.

            3.4 Adjustment for Common Stock Issue. If the Company issues shares
of Common Stock for a consideration per share less than the Current Market Price
per share of Common Stock on the date the Company fixes the offering price of
such additional shares, the Stock Purchase Price shall be adjusted in accordance
with the formula:

                           P
                     O + ----

                           M
            E(1)  =  E x ----
                           A

where:

            E(1)  =  the adjusted Stock Purchase Price.

            E  =  the then current Stock Purchase Price.

            O  =  the number of shares outstanding immediately prior to the
                  issuance of such additional shares.

            P  =  the aggregate consideration received for the issuance of
                  such additional shares.

            M  =  the Current Market Price per share of Common Stock on the
                  date of issuance of such additional shares.

            A  =  the number of shares outstanding immediately after the
                  issuance of such additional shares.

The adjustment shall be made successively whenever any such issuance is made,
and shall become effective immediately after such issuance. This subsection 3.4
does not apply to:

                                   Exhibit 4-5
<PAGE>

                  (a) the exercise of the Warrants,

                  (b) rights, options, warrants or other distributions referred
to in subsections 3.2, 3.3 or 3.5,

                  (c) Common Stock issued to the Company's directors, employees
and non-employee service providers under bona fide benefit plans adopted by the
Board of Directors and, when required by law, approved by the holders of Common
Stock, if such Common Stock would otherwise be covered by this subsection 3.4,
or

                  (d) Common Stock issued in a bona fide public offering
pursuant to a firm commitment underwriting.

            3.5 Adjustment for Convertible Securities Issue. If the Company
issues any securities convertible into or exchangeable for Common Stock (other
than securities issued in transactions described in subsections 3.2 and 3.3 and
other than securities issued to the Company's directors, employees and
non-employee service providers under bona fide benefit plans adopted by the
Board of Directors and, when required by law, approved by the holders of Common
Stock, if such securities would otherwise be covered by this subsection 3.5) for
a consideration per share of Common Stock initially deliverable upon conversion
or exchange of such securities less than the Current Market Price per share of
Common Stock on the date of issuance of such securities, the Stock Purchase
Price shall be adjusted in accordance with this formula:

                              P
                     O  +  ------

                              M
            E(1)  =  E  x  ------
                            O + D

where:

            E(1)  =  the adjusted Stock Purchase Price.

            E  =  the then current Stock Purchase Price.

            O  =  the number of shares outstanding immediately prior to the
                  issuance of such securities.

            P  =  the aggregate consideration received for the issuance of such
                  securities.

            M  =  the Current Market Price per share of Common Stock on the date
                  of issuance of such securities.

            D  =  the maximum number of shares deliverable upon conversion or in
                  exchange for such securities at the initial conversion or
                  exchange rate.

                                   Exhibit 4-6
<PAGE>

The adjustment shall be made successively whenever any such issuance is made,
and shall become effective immediately after such issuance.

            If all of the Common Stock deliverable upon conversion or exchange
of such securities have not been issued when such securities are no longer
outstanding, then the Stock Purchase Price shall promptly be readjusted to the
Stock Purchase Price which would then be in effect had the adjustment upon the
issuance of such securities been made on the basis of the actual number of
shares of Common Stock issued upon conversion or exchange of such securities.

            3.6 Current Market Price. As used in this Agreement, the "Current
Market Price" per share of Common Stock on any date is the average of the Quoted
Prices of the Common Stock for each trading day during the period commencing 30
trading days before such date and ending on the date one trading day prior to
such date. The "Quoted Price" of the Common Stock is the last reported closing
price of the Common Stock as reported by Nasdaq National Market, or if the
Common Stock is listed on a national securities exchange, the last reported
closing price of the Common Stock on such exchange (which shall be for
consolidated trading if applicable to such exchange), or if neither so reported
or listed, the last reported bid price of the Common Stock. In the absence of
one or more such quotations, the Board of Directors of the Company shall
determine the Current Market Price on the basis of such quotations as it in good
faith considers appropriate. If at any time the Common Stock is not listed on
any securities exchange or quoted in the Nasdaq System or the over-the-counter
market, the current fair market value of the Common Stock shall be determined in
good faith by the Board of Directors of the Company.

            3.7 Consideration Received. For purposes of any computation
respecting consideration received pursuant to subsections 3.4 and 3.5, the
following shall apply:

                  (a) in the case of the issuance of shares of Common Stock for
cash, the consideration shall be the amount of such cash, provided that in no
case shall any deduction be made for any commissions, discounts or other
expenses incurred by the Company for any underwriting of the issue or otherwise
in connection therewith;

                  (b) in the case of the issuance of shares of Common Stock for
a consideration in whole or in part other than cash, the consideration other
than cash shall be deemed to be the fair market value thereof as determined in
good faith by the Board of Directors (irrespective of the accounting treatment
thereof), whose determination shall be conclusive, and described in a Board
resolution; and

      (c) in the case of the issuance of securities convertible into or
exchangeable for shares, the aggregate consideration received therefor shall be
deemed to be the consideration received by the Company for the issuance of such
securities plus the additional minimum consideration, if any, to be received by
the Company upon the conversion or exchange thereof (the consideration in each
case to be determined in the same manner as provided in clauses (i) and (ii) of
this subsection).

                                   Exhibit 4-7
<PAGE>

            3.8 When Adjustments May Be Deferred.

      (a) No adjustment in the Stock Purchase Price need be made unless the
adjustment would require an increase or decrease of at least 1% in the Stock
Purchase Price. Any adjustments that are not made shall be carried forward and
taken into account in any subsequent adjustment. All calculations under this
Section shall be made to the nearest cent or to the nearest 1/100th of a share,
as the case may be.

      (b) No adjustment in the Stock Purchase Price shall be made pursuant to
Section 3.4 or 3.5 herein during the 180 day period following the date hereof.

      (c) No adjustment in the Stock Purchase Price need be made pursuant to
Section 3.4 or 3.5 herein unless and until the aggregate Dilution incurred by
Holder in all issuances to which such sections apply exceeds $200,000. For
purposes of this section, any Dilution that would have occurred during the 180
day period following the date hereof without reference to Section 3.8(b) shall
not be included in determining the $200,000 threshold. For the purposes of this
Section, the "Dilution" incurred by Holder in any issuance shall be derived in
accordance with the following formula:

                                            H
            Dilution  =  N  x   (M - P) x ------
                                            A

where:

            N  =  the number of additional shares of Common Stock issued or
                  issuable upon exercise of the rights, options or warrants
                  offered.

            M  =  the Current Market Price per share of Common Stock on the date
                  of issuance of such additional shares or the offering of such
                  rights, options or warrants.

            P  =  the issuance price per share of the additional shares or the
                  exercise price per share of the additional shares issuable
                  upon exercise of the rights, options or warrants.

            H  =  the maximum number of shares into which this Warrant may be
                  converted.

            A  =  the number of shares outstanding immediately after the
                  issuance of such additional shares or as would be outstanding
                  upon exercise of all rights, options or warrants offered.

            3.9 When No Adjustment Required. No adjustment need be made for a
transaction referred to in subsections 3.1 through 3.5 if:

                                   Exhibit 4-8
<PAGE>

                  (a) Warrant holders are to participate in the transaction on a
basis and with notice that the Board of Directors determines to be fair and
appropriate in light of the basis and notice on which holders of Common Stock
participate in the transaction. Further, no adjustment need be made for rights
to purchase Common Stock pursuant to a Company plan for reinvestment of
dividends or interest; or

                  (b) there is a change in the par value or no par value of the
Common Stock; or

                  (c) the Company distributes or issues rights to all holders of
its Common Stock pursuant to a shareholder rights plan, provided that, upon
exercise of the Warrant, each holder thereof receives the same type and number
of unexpired rights it would have received (as adjusted for any event described
in Section 3.1 or 3.12) had it exercised its Warrant, and been a holder of the
Warrant Shares issuable upon exercise thereof, prior to the record date for such
distribution or issuance; or

                  (d) the Warrant becomes convertible into cash, no adjustment
need be made thereafter as to the cash and interest will not accrue on the cash.

            3.10 Notice of Adjustment. Whenever the Stock Purchase Price is
adjusted, the Company shall provide the notices required by Section 8 hereof.

            3.11 [Reserved].

            3.12 Reorganization of Company. If any reclassification of the
Common Stock of the Company or any consolidation or merger of the Company with
another entity, or the sale or lease of all or substantially all of the
Company's assets to another entity shall be effected in such a way that holders
of the Common Stock of the Company shall be entitled to receive stock,
securities or assets with respect to or in exchange for such Common Stock, then,
as a condition precedent to such reclassification, consolidation, merger, sale
or lease, lawful and adequate provisions shall be made whereby the Warrant
holder shall thereafter have the right to purchase and receive upon the basis
and the terms and conditions specified in this Warrant and in lieu of the shares
of Common Stock immediately theretofore purchasable and receivable upon the
exercise of the rights represented hereby, such shares of stock, securities or
assets as may be issued or payable in such reclassification, consolidation,
merger, sale or lease with respect to or in exchange for the number of shares of
Common Stock purchasable and receivable upon the exercise of the rights
represented hereby had such rights been exercised immediately prior thereto, and
in any such case appropriate provision shall be made with respect to the rights
and interests of the holders of the Warrant to the end that the provisions
hereof (including without limitation provisions for adjustments of the Stock
Purchase Price and of the number of shares of Common Stock purchasable and
receivable upon the exercise of the Warrant) shall thereafter be applicable, as
nearly as may be, in relation to any shares of stock, securities or assets
thereafter deliverable upon the exercise hereof. The Company will not effect any
such reclassification, consolidation, merger, sale or lease, unless prior to the
consummation thereof the successor corporation (if other than the Company)
resulting from such reclassification, consolidation or merger or the corporation
purchasing or leasing such assets shall assume by a supplemental

                                   Exhibit 4-9
<PAGE>

Warrant Agreement, executed and mailed or delivered to the holders of the
Warrant at the last address thereof appearing on the books of Company, the
obligation to deliver to such holders such shares of stock, securities or assets
as, in accordance with the foregoing provisions, such holders may be entitled to
purchase.

                  (a) If the issuer of securities deliverable upon exercise of
Warrants under the supplemental Warrant Agreement is an affiliate of the formed,
surviving, transferee or lessee corporation, that issuer shall join in the
supplemental Warrant Agreement.

                  (b) If this subsection 3.12 applies, subsections 3.1 through
3.5 do not apply.

            3.13 When Issuance or Payment May Be Deferred. In any case in which
this Section 3 shall require that an adjustment in the Stock Purchase Price be
made effective as of a record date for a specified event, the Company may elect
to defer until the occurrence of such event (i) issuing to the holder of any
Warrant exercised after such record date the Warrant Shares and other capital
stock of the Company, if any, issuable upon such exercise over and above the
Warrant Shares and other capital stock of the Company, if any, issuable upon
such exercise on the basis of the Stock Purchase Price and (ii) paying to such
holder any amount in cash in lieu of a fractional share pursuant to Section 11;
provided, however, that the Company shall deliver to such holder a due bill or
other appropriate instrument evidencing such holder's right to receive such
additional Warrant Shares, other capital stock and cash upon the occurrence of
the event requiring such adjustment.

            3.14 Adjustment in Number of Shares. Upon each adjustment of the
Stock Purchase Price pursuant to Section 3.1 or 3.2, the Warrant outstanding
prior to the making of the adjustment in the Stock Purchase Price shall
thereafter evidence the right to receive upon payment of the adjusted Stock
Purchase Price that number of shares of Common Stock (calculated to the nearest
hundredth) obtained from the following formula:

                             E
            N(1)  =  N  x  ------
                            E(1)

where:

            N(1)  =  the adjusted number of Warrant Shares issuable upon
                     exercise of a Warrant by payment of the adjusted Stock
                     Purchase Price.

            N  =  the number of Warrant Shares previously issuable upon exercise
                  of a Warrant by payment of the Stock Purchase Price prior to
                  adjustment.

            E(1)  =  the adjusted Stock Purchase Price.

            E  =  the Stock Purchase Price prior to adjustment.

                                  Exhibit 4-10
<PAGE>

There shall be no adjustment in the number of shares of Common Stock that the
Warrant evidences the right to receive in the case of any adjustment to the
Stock Purchase Price pursuant to Section , 3.3, 3.4 or 3.5. With respect to
adjustments of the Stock Purchase Price pursuant to Section 3.2, there shall be
no further corresponding adjustments in the number of shares of Common Stock
pursuant to this Section 3.14 that the Warrant evidences the right to receive if
such further adjustment would result in the potential issuance upon exercise of
this Warrant of more than nine and ninety-nine one-hundredths percent (9.99%) of
the number of shares of Common Stock outstanding as of the date of this Warrant.

            3.15 Form of Warrant. Irrespective of any adjustments in the Stock
Purchase Price or the number or kind of shares purchasable upon the exercise of
the Warrant, any Warrant theretofore or thereafter issued may continue to
express the same price and number and kind of shares as are stated in the
Warrant initially issuable.

      4.    ISSUANCES AND TRANSFER TAXES.

            The issuance of certificates in the name of the Holder for the
Warrant Shares upon the exercise of this Warrant shall be made without charge to
the Holder of this Warrant for any issue tax in respect thereof. The Holder
shall pay all stock transfer taxes, if any, in respect of any transfer of this
Warrant or any Warrant Shares.

      5.    NO VOTING OR DIVIDEND RIGHTS; LIMITATION OF LIABILITY.

            Nothing contained in this Warrant shall be construed as conferring
upon the Holder hereof the right to vote or to consent or to receive notice as a
stockholder in respect of meetings of stockholders for the election of directors
of the Company or any other matters or any rights whatsoever as a stockholder of
the Company. Except for the adjustment to the Stock Purchase Price pursuant to
Section 3.1 hereof in the event of a dividend on the Common Stock payable in
shares of Common Stock, no dividends or interest shall be payable or accrued in
respect of this Warrant or the interest represented hereby or the shares
purchasable hereunder until, and only to the extent that, this Warrant shall
have been exercised.

      6.    RESTRICTIONS ON TRANSFERABILITY OF SECURITIES; COMPLIANCE WITH
            SECURITIES ACT.

            The Warrant Shares shall not be transferable except upon the
conditions specified in the Warrant Purchase Agreement.

      7.    MODIFICATION AND WAIVER.

            This Warrant is irrevocable and non-cancelable, and any provision
hereof may be changed, waived, discharged or terminated only by an instrument in
writing signed by the party against which enforcement of the same is sought.

                                  Exhibit 4-11
<PAGE>

        8.     NOTICES.

            All notices and other communications required or permitted hereunder
shall be effective upon receipt and shall be in writing and may be delivered in
person, by facsimile, overnight delivery service or U.S. mail, in which event it
may be mailed by first-class, certified or registered, postage prepaid,
addressed:

        if to the Holder, at

                      Amgen Inc.
                      One Amgen Center Drive
                      Thousand Oaks, CA  91320-1789
                      Attention:  Corporate Secretary
                      Fax: (805) 447-1010

        with a copy to

                      Latham & Watkins
                      633 West Fifth Street, Suite 4000
                      Los Angeles, California 90071-2007
                      Attention:  Gary Olson
                      Fax: (213) 891-8763

        or

        if to the Company, at

                      Hyseq, Inc.
                      675 Almanor Avenue
                      Sunnyvale, CA  94085
                      Attention:  President
                      Fax: (408) 524-8141

        with a copy to

                      Brobeck, Phleger & Harrison LLP
                      Two Embarcadero Place
                      2200 Geng Road
                      Palo Alto, CA 94303
                      Attention: Timothy R. Curry
                      Fax: (650) 496-2715

or in any case at such other address as the Holder or the Company shall have
furnished to the other in writing.

                                  Exhibit 4-12
<PAGE>

      9.    DESCRIPTIVE HEADINGS AND GOVERNING LAW.

            The descriptive headings of the Sections and paragraphs of this
Warrant are inserted for convenience only and do not constitute a part of this
Warrant. This Warrant shall be construed and enforced in accordance with, and
the rights of the parties shall be governed by, the laws of the State of
California without regard to conflict of laws.

      10.   LOST WARRANTS OR STOCK CERTIFICATES.

            The Company represents and warrants to the Holder that upon receipt
of evidence reasonably satisfactory to the Company of the loss, theft,
destruction, or mutilation of any Warrant or stock certificate and, in the case
of any such loss, theft or destruction, upon receipt of an indemnity and, if
requested, bond reasonably satisfactory to the Company, or in the case of any
such mutilation upon surrender and cancellation of such Warrant or stock
certificate, the Company at its expense will make and deliver a new Warrant or
stock certificate, of like tenor, in lieu of the lost, stolen, destroyed or
mutilated Warrant or stock certificate.

      11.   FRACTIONAL SHARES.

            No fractional shares shall be issued upon exercise of this Warrant.
The Company shall, in lieu of issuing any fractional share, pay the Holder
entitled to such fraction a sum in cash equal to such fraction multiplied by the
market price of the Common Stock (the market price determined, for any date, as
the average of the closing prices of the Common Stock on the Nasdaq National
Market (or such other principal securities exchange or automated quotation
system upon which the Common Stock may then be listed for public trading) for
the five immediately preceding trading days on such exchange).

      12.   NO IMPAIRMENT.

            The Company will not, by amendment of its Articles of Incorporation
or bylaws, or through reorganization, consolidation, merger, dissolution, issue
or sale of securities, sale of assets or any other voluntary action, avoid or
seek to avoid the observance or performance of any of the terms of this Warrant,
but will at all times in good faith assist in the carrying out of all such terms
and in the taking of all such action as may be necessary or appropriate in order
to protect the rights of the Holder of this Warrant against impairment. Without
limiting the generality of the foregoing, the Company (a) will not increase the
par value of any shares of stock issuable upon the exercise of this Warrant
above the amount payable therefor upon such exercise, and (b) will take all such
action as may be necessary or appropriate in order that the Company may validly
and legally issue fully paid and non-assessable shares of Common Stock upon
exercise of this Warrant.

                                  Exhibit 4-13
<PAGE>

      IN WITNESS WHEREOF, the Company has caused this Warrant to be executed by
its officers, thereunto duly authorized this 8th day of January, 2002.

                                        HYSEQ, INC.

                                        D.B.A.  HYSEQ PHARMACEUTICALS

                                        ----------------------------------------
                                        By
                                          --------------------------------------
                                        Title
                                             -----------------------------------

                           [Signature Page to Warrant]
                                  Exhibit 4-14
<PAGE>

                              NOTICE OF CONVERSION

      (To be signed only upon exercise of Warrant)

      To:    Hyseq, Inc.

            The undersigned, the Holder of the within Warrant, hereby
irrevocably elects to exercise the purchase right represented by such Warrant
for, and to purchase thereunder, _________________ shares of common stock, par
value $0.001 per share, of Hyseq, Inc. (the "Company") and herewith makes
payment therefor in cash by remitting $________ and requests that the
certificates for such shares be issued in the name of, and delivered to,

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

--------------------------------------------------------------------------------
whose address is
                ---------------------------------------------------------------.

            Capitalized terms used but not defined herein shall have the
meanings ascribed to such terms in the Warrant.

            DATED:
                  ----------------------

                                             AMGEN INC.

                                             By
                                               ---------------------------------
                                             Title
                                                  ------------------------------

                                  Exhibit 4-15<PAGE>

                                                                   EXHIBIT 10.28

                            COLLABORATION AGREEMENT

                                 BY AND BETWEEN

                                   AMGEN INC.

                                       AND

                                   HYSEQ, INC.

                         (D.B.A. HYSEQ PHARMACEUTICALS)

                                 JANUARY 8, 2002

CERTAIN INFORMATION IN THIS EXHIBIT HAS BEEN OMITTED AND FILED SEPARATELY WITH
THE COMMISSION. CONFIDENTIAL TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE
OMITTED PORTIONS.

<PAGE>

                             COLLABORATION AGREEMENT

      THIS COLLABORATION AGREEMENT (the "Agreement") is made effective as of
January 8, 2002 (the "Effective Date") by and between AMGEN INC., a Delaware
corporation having its principal place of business at One Amgen Center Drive,
Thousand Oaks, California 91320-1799 ("Amgen") and HYSEQ, INC., d.b.a. HYSEQ
PHARMACEUTICALS, a Nevada corporation having its principal place of business at
670 Almanor Avenue, Sunnyvale, California 94085-1710 ("Hyseq"). Amgen and Hyseq
are sometimes referred to herein individually as a "Party" and collectively as
the "Parties".

                                    RECITALS

      WHEREAS, Amgen has developed certain technology and know-how which relates
to a protein known as Alfimeprase;

      WHEREAS, Hyseq has technology and know-how and significant experience and
expertise in the research and development of pharmaceutical products that may be
particularly well suited to develop and market a product such as Alfimeprase;

      WHEREAS, Hyseq now wishes to collaborate with Amgen in the further
research, development and commercialization of Alfimeprase on the terms and
conditions set forth herein;

      WHEREAS, the Parties believe it to be in their mutual interest to combine
their mutual experience, know-how and expertise and to grant each other such
intellectual property licenses and other rights as are necessary to diligently
continue the research and development begun by Amgen so as to commercialize
Alfimeprase or one or more products resulting from the aforesaid continuing
research and development.

      NOW THEREFORE, based on the foregoing premises and the mutual covenants
and obligations set forth below, the Parties agree as follows:

                                    ARTICLE 1
                                   DEFINITIONS

      Capitalized terms used but not otherwise defined herein have the meanings
provided in EXHIBIT A hereto.

                                    ARTICLE 2
                            COLLABORATION GOVERNANCE

      2.1 COLLABORATION. The Parties agree to jointly Develop and Commercialize
Collaboration Products under the terms of this Agreement.

      2.2 STEERING COMMITTEE. As soon as practicable following the Effective
Date, the Parties shall establish a Committee (the "Steering Committee")
comprised of two (2) senior

                                       1.
<PAGE>

officers or managers from each of Hyseq and Amgen. The Steering Committee shall
follow the organizational and meeting procedures set forth in Section 2.4.

      2.3 STEERING COMMITTEE RESPONSIBILITIES. The Steering Committee shall be
responsible for overseeing and managing the collaboration, including, without
limitation the following functions:

      (a) determining the overall strategy for the Development, manufacturing
and Commercialization of all Collaboration Products in the manner contemplated
by this Agreement;

      (b) establishing a governance structure for and coordinating the
activities of the Parties hereunder including, to the extent necessary,
establishing certain operating committees to oversee certain activities such as
Development, finance, manufacturing and Commercialization (the operating
committees shall be subordinate to the Steering Committee and shall include
individuals with expertise and responsibilities in the relevant areas);

      (c) reviewing and approving the Program Plan;

      (d) reviewing the activities and Collaboration Expenditures compared to
the Program Plan and determining whether any changes are necessary, given the
then-current progress and results;

      (e) approving target product profiles for Collaboration Products,
including indications, in addition to peripheral arterial occlusion (PAO), for
which the Collaboration Products will be further Developed and Commercialized;

      (f) determining which Collaboration Products will be Developed and
Commercialized;

      (g) facilitating the exchange of all data, Information, Materials or
results relating to Collaboration Products, including developing report formats
to facilitate the respective activities and responsibilities of the Parties; and

      (h) performing such other functions as appropriate to further the purposes
of the collaboration as determined by the Parties.

      2.4 DECISION MAKING; ADMINISTRATIVE MATTERS.

      (a) Decision Making. All decisions of the Steering Committee shall be made
by the[***] of Hyseq and Amgen, with the representatives of each Party who are
members of the Steering Committee [***].

      (b) Dispute Resolution. If the Steering Committee is unable to reach [***]
agreement on any issue within a period of [***] after receiving notification of
such dispute regarding any aspect under this Agreement, then the final
decision-making authority for any such matter shall be determined, depending
upon the subject matter of the unresolved issue, as follows:

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                       2.
<PAGE>

            (i) [***]: Other than as set forth in this Section 2.4(b)(i), [***]
      shall apply to [***] with the exception of the following issues, which
      will at all times require [***]: setting product specifications and
      product forecasts (as detailed in the Development Plan and/or Commercial
      Plan sections of the Program Plan); setting the [***] charged to the
      Operating Profit or Loss account; and deciding whether to [***] for the
      generation of sufficient clinical data to file for and obtain Regulatory
      Approval of a first Collaboration Product.

            (ii) [***]: Other than as set forth in this Section 2.4(b)(ii),
      [***] shall apply to [***], with the exception of the following issues,
      which will at all times require [***]: setting product specifications and
      product forecasts (as detailed in the Development Plan and/or the
      Commercial Plan sections of the Program Plan); and setting the [***]
      charged to the Operating Profit or Loss account.

            (iii) [***]: Other than as set forth in this Section 2.4(b)(iii),
      [***]shall apply to [***], with the exception of the following issues,
      which will at all times require [***]: setting the [***] charged to the
      Operating Profit or Loss account; and Recalling Collaboration Products
      (provided that regulatory timeframes or safety considerations do not
      require early action by a Party before action by the Steering Committee).

            (iv) [***]: Other than as set forth in this Section 2.4(b)(iv),
      [***]shall apply to [***], with the exception of the following issues,
      which will at all times require [***]: setting the [***] charged to the
      Operating Profit or Loss account.

            (v) All other decisions: The Parties shall attempt to resolve
      disputes concerning matters not listed in (i)--(iv) above in accordance
      with the provisions of Article 17, below.

For the avoidance of doubt, [***] as set forth in Sections 2.4(b)(i)-(iv) shall
not relieve the Party [***] from any of its representations, warranties and/or
covenants as set forth in Article 13 nor shall it enable such Party to
unilaterally modify or amend the terms of this Agreement.

      (c) Administrative Matters. The Steering Committee shall establish its own
procedural rules for its operation, consistent with the terms of this Section
2.4. A chairperson for the Steering Committee shall be appointed from among its
members. The chairperson shall be appointed on an annual basis and shall
alternate each Calendar Year between a Hyseq representative and an Amgen
representative, with Hyseq being responsible for designating the chairperson for
the first Calendar Year after the Effective Date. The chairperson shall be
responsible for calling meetings of the Steering Committee and for leading the
meetings. A Steering Committee member of the Party hosting a meeting of the
Steering Committee shall serve as secretary of that meeting. Within [***]
following each meeting, the secretary of such meeting shall prepare and
distribute to all members of the Steering Committee the minutes of the meeting.
Such minutes shall provide a reasonably detailed description of the meeting
discussions and a list of any actions, decisions or determinations approved by
the Steering Committee. The minutes of each Steering Committee meeting shall be
approved or disapproved,

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                       3.
<PAGE>

and revised as necessary, at the next meeting. Final minutes of each meeting
shall be distributed to the members of the Steering Committee by the
chairperson.

      (d) Meetings. The Steering Committee shall meet at least [***] per
Calendar Year. Such meetings shall alternate between Amgen and Hyseq locations
and be held at such times as are mutually agreed upon by the Steering Committee
and shall be conducted in person, unless approved by the chairperson to conduct
such meetings by video conference or teleconference. The first meeting shall be
held at Amgen's facilities.

      (e) Attendance at Meetings. If a Party's representative is unable to
attend a meeting, such Party may designate an alternate representative to attend
such meeting. In addition, each Party may, at its discretion (and with the
consent of the other Party), invite additional employees, consultants or
scientific advisors to attend any Steering Committee meetings.

                                    ARTICLE 3
                                   DEVELOPMENT

      3.1 DEVELOPMENT. Following the Effective Date, the Parties shall undertake
Development of the Collaboration Products in the manner contemplated in this
Agreement. To the extent applicable, each Party agrees to maintain all
regulatory and governmental permits, licenses and approvals and to comply with
all laws, rules and regulations that are applicable to each such Party's
activities and the particular stage of Development of the Collaboration Products
including, without limitation, GLPs, GCPs and GMPs, as such standards are
defined in accordance with the applicable guidance and regulations including the
International Conference of Harmonization (ICH), the U.S. Food, Drug and
Cosmetic Act, 21 C.F.R.(s) 210 et seq. and the regulations promulgated
thereunder, and any amendments thereto and the regulations promulgated
thereunder, and the equivalent laws, rules and regulations of other countries in
the Territory.

      3.2 HYSEQ RESPONSIBILITIES.

      (a) Hyseq shall be designated as the "Development Lead." Hyseq shall be
responsible for preparing and submitting the Development Plan section of the
Program Plan to and for approval by the Steering Committee, and shall update the
Development Plan on an annual basis, in time for the annual budget cycle of each
of the Parties; provided however, it is acknowledged and agreed that the
Development Plan may need to be modified from time-to-time between annual
updates, based upon the results of clinical trials and other unanticipated
events.[***]. Hyseq shall have responsibility for all aspects of Developing the
Collaboration Products in the Territory, including making all strategic and
tactical decisions with respect thereto in accordance with the Development Plan
and establishing the methods and means by which it performs its services under
this Agreement (including the management of permitted subcontractors, pursuant
to Section 18.7). Hyseq [***] in accordance with the Development Plan approved
by the Steering Committee, [***].

      (b) Upon the request of Hyseq, Amgen [***] to assume certain Development
responsibilities in support of Hyseq's carrying out the activities within the
Development Plan.

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                       4.
<PAGE>

Prior to assuming any such responsibility, Amgen shall provide to Hyseq, for
approval by the Steering Committee and inclusion within the Development Plan,
the estimated budget for carrying out any such responsibility and may thereafter
charge the Operating Profit or Loss account for any approved expenditures.

      (c) Each Party shall be responsible for carrying out its assigned
activities in accordance with the Development Plan. These activities shall
include, without limitation (i) investigating peripheral arterial occlusion as
the primary indication for which Collaboration Products will be developed, and
identifying other indications for which Collaboration Products will be
Developed; (ii) identifying and carrying out all major Development tasks to be
conducted prior to submission of filings for Regulatory Approval of a
Collaboration Product for a particular indication; (iii) identifying key
Development objectives, expected associated resources, risk factors, timelines,
go/no go decision points and relevant decision criteria; (iv) carrying out all
aspects of (e.g., designing studies and protocols and conducting), and preparing
the associated Regulatory Plan for, all clinical trials necessary to obtain
Regulatory Approval for each indication pursued, as well as establishing new
dosage forms, new formulations or other enhancements of approved Collaboration
Products (but excluding Post-Approval Clinical Studies) including, but not
limited to (1) establishing/contracting with clinical sites, investigators and
CROs, (2) enrolling clinical study patients, (3) organizing investigator
meetings, scientific meetings, advisory panel workshops and regulatory meetings,
and (4) analyzing, summarizing and presenting clinical study results; (v)
performing any other additional research and pre-clinical research in support of
the clinical development of Collaboration Products; (vi) forecasting clinical
manufacturing production requirements; (vii) Regulatory Authority reporting on
study design, study outcome, other communications and regulatory filings (to the
extent not covered by a Regulatory Plan); (viii) establishing material transfer
and collaboration agreements, pursuant to Section 9.13, prior to the Transition
Date of the first Collaboration Product; and (ix) preparing publications and
presentations of data regarding Collaboration Products generated prior to the
Transition Date of a Collaboration Product.

      3.3 INFORMATION AND DATA. Hyseq shall promptly disclose to Amgen all
material scientific or technical information relating to any Collaboration
Product that it discovers in the course of Development activities, promptly
[***]. Hyseq shall maintain a database which contains (a) all clinical trial
data accumulated from clinical trials of all Collaboration Products, (b) all
safety data, and (c) all adverse reaction information for all Collaboration
Products during Development. On an annual basis, Hyseq shall provide Amgen with
written summaries of all pre-clinical and clinical data generated by Hyseq with
respect to Collaboration Products, as well as all such pre-clinical and clinical
data in computer readable format requested by Amgen. Amgen shall be entitled to
have access, during regular business hours and upon reasonable advance notice,
to such pre-clinical and clinical data maintained by Hyseq (including all
clinical trial databases, in a computer readable format requested by Amgen).
[***] interest in all data and Information generated as part of the Development
of Collaboration Products, including all data accumulated from all clinical
trials of each Collaboration Product.

      3.4 AUDIT. Amgen shall have the right to conduct reasonable quality
assurance audits with respect to all facilities, operations and laboratories
(and any records related thereto) of Hyseq or Third Party subcontractors, where
Development activities are conducted, as is reasonably necessary solely for the
purpose of verifying Hyseq's conformance with applicable

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                                       5.
<PAGE>

cGMP, cGLP, cGCP and other regulatory requirements. Hyseq shall have the right
to conduct reasonable quality assurance audits with respect to all facilities,
operations and laboratories (and any records related thereto) of Amgen where
Development activities are conducted [***] to permit Hyseq to carry out its
activities as Development Lead and/or Regulatory Lead and/or Commercial Lead (as
determined hereunder). Such audits shall be conducted upon reasonable notice
during reasonable business hours.

                                    ARTICLE 4
                                   REGULATORY

      4.1 REGULATORY LEAD. The Development Lead (Hyseq) shall be responsible for
all regulatory matters for Development, i.e., concerning each indication for a
Collaboration Product prior to the Transition Date for such Collaboration
Product in such indication. On an indication-by-indication basis, the Commercial
Lead (as determined pursuant to Sections 5.1 and 5.8) shall be responsible for
all regulatory matters for Commercialization, i.e., concerning each indication
for a Collaboration Product upon the Transition Date for such Collaboration
Product in each such indication including, without limitation, the filing and
support of any Drug Approval Applications and matters concerning Post-Approval
Clinical Studies. Each Party having responsibility for regulatory matters during
the time periods (pre- and post-Transition Date) as set forth in this Section
4.1 shall be designated as the "Regulatory Lead" for such regulatory matters
during such time periods.

      4.2 RESPONSIBILITIES AND RIGHTS OF REGULATORY LEAD. During the time period
for which it is responsible for regulatory matters, the Regulatory Lead for an
indication shall be the trial sponsor with Regulatory Authorities and shall be
responsible for preparing and submitting, with respect to such indication, a
draft Regulatory Plan section of the Program Plan to the Steering Committee for
its approval, as well as updating the Regulatory Plan on an annual basis, in
time for the annual budget cycle of each of the Parties; provided however, it is
acknowledged and agreed that the Regulatory Plan may need to be modified from
time-to-time between annual updates, based upon the results of clinical trials
and other unanticipated events. [***] With respect to regulatory matters for
which it is responsible, the Regulatory Lead for an indication shall have the
right to monitor, review and direct all aspects of regulatory matters regarding
Collaboration Products for such indication in the Territory, including making
all strategic and tactical decisions with respect thereto (in accordance with
the Regulatory Plan) and establishing the methods and means by which it performs
such services, including the management of permitted subcontractors, pursuant to
Section 18.7. In accordance with Section 4.7, the Regulatory Lead shall have
responsibility for all associated official correspondence, communications and
Regulatory Filings with Regulatory Authorities regarding such matters. The
Regulatory Lead shall not transfer title in or otherwise attempt in any manner
to dispose of any Regulatory Filings or Regulatory Approvals or other
governmental licenses, approvals or certificates for Collaboration Products in
the Territory, or otherwise impair the other Party's rights in such Regulatory
Filings or Regulatory Approvals, or other governmental licenses, approvals or
certificates.

      4.3 TRANSFER OF IND. As of the Effective Date, Amgen owns in its own name
a certain IND filing for Alfimeprase in the Territory, which is set forth in
Exhibit C. Subject to

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                                       6.
<PAGE>

Amgen's rights pursuant to this Agreement, Amgen hereby assigns to Hyseq Amgen's
entire right, title and interest in and to such IND set forth in Exhibit C;
Hyseq shall then assume all responsibility (and become the sponsor and party of
record) for regulatory matters therewith, and shall thereafter be designated the
"Regulatory Lead" therefor. Hyseq, in consultation with Amgen, shall prepare,
file and maintain all regulatory documentation and perform all applicable
regulatory activities for each Collaboration Product prior to its respective
Transition Date. No later than [***] after the Effective Date, Amgen shall
notify Regulatory Authorities in the Territory of the transfer and, [***], shall
take all actions reasonably necessary to effect or evidence the transfer of such
IND to Hyseq. [***] Notwithstanding anything to the contrary in this Agreement,
Hyseq shall have the right to receive from Amgen, and Amgen shall provide to
Hyseq, any regulatory data or information to which Hyseq, as the holder of any
IND in the Territory, is required by law, rule, regulation or a Regulatory
Authority having jurisdiction in the Territory, to have access, or which Hyseq
reasonably requires in order to carry out its responsibilities as Development
Lead and/or Regulatory Lead and/or Commercial Lead; [***] such law, rule,
regulation or Regulatory Authority [***] carry out its responsibilities as
Development, Regulatory and/or Commercial Lead.

      4.4 DRUG APPROVAL APPLICATIONS.

      (a) After the Transition Date for a Collaboration Product in an
indication, the Commercial Lead shall become the Regulatory Lead with respect to
such indication, with responsibility for filing Drug Approval Applications and
seeking Regulatory Approvals for such Collaboration Product in the Territory.

      (b) To the extent that it is the Commercial Lead, Amgen shall have the
right to receive from Hyseq, and Hyseq shall provide to Amgen any regulatory
data or information which Amgen requires to file the Drug Approval Applications,
or to which Amgen, as the holder of any Drug Approval Applications in the
Territory, is required by law, rule, regulation or a Regulatory Authority having
jurisdiction in the Territory, to have access, or which Amgen reasonably
requires in order to carry out its responsibilities as Commercial Lead; but
Amgen shall only be entitled to use such regulatory data or information to the
extent it is reasonably required for Amgen to carry out its responsibilities as
Commercial Lead or as a Regulatory Lead. To the extent that Amgen is the
Commercial Lead, Hyseq shall also grant Amgen a right of access and reference to
(and name it a party of record on) all INDs and shall promptly notify Regulatory
Authorities in the Territory of (and [***]thereafter take all actions reasonably
necessary to effect or evidence) the right of access and reference to (and
naming Amgen as a sponsor and party of record on) such INDs.

      (c) Prior to submitting any Drug Approval Application the Commercial Lead,
through the Steering Committee, shall consult with the other Party about the
content and scope of such Drug Approval Applications. The Commercial Lead shall
own (be the sponsor and party of record of) all Drug Approval Applications for
Collaboration Products in the Territory.

      4.5 TRANSFER OF REGULATORY FILINGS AND REGULATORY APPROVALS. If ownership
of a Regulatory Filing or Regulatory Approval in any country cannot be
transferred from the owning Party to the other Party pursuant to any one of
Sections 4.3, 4.4(b), 5.8(b), 16.9(a)(iii) or 16.9(c)(ii), the owning Party
shall grant to the other Party an exclusive right of access and

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                                       7.
<PAGE>

reference to such Regulatory Filing or Regulatory Approval in such country in
order to enable the other Party to become a sponsor and party of record of an
IND. If such right of access and reference is not sufficient to permit the other
Party to file a Drug Approval Application and receive Regulatory Approval or to
Develop, manufacture or Commercialize a Collaboration Product, the owning Party
shall provide the other Party with any and all information necessary for the
other Party to carry out such activities and to receive Regulatory Approval in
its own name.

      4.6 ADVERSE EVENT REPORTING; CUSTOMER COMPLAINTS.

      (a) Each Party shall maintain a record of all non-medical and medical
product-related complaints and reports of adverse events that it receives with
respect to any Collaboration Product. Each Party shall notify the other Party of
any complaint received by it and, within [***](but, in the event of serious
adverse events,) of the initial receipt, provide the other Party with a copy of
such complaint(s) and adverse event reports.

      (b) On an indication-by-indication basis, after the Effective Date and
prior to the Transition Date for a Collaboration Product in an indication, Hyseq
(as the IND sponsor and party of record) shall be responsible for reporting to
Regulatory Authorities any adverse experience and safety issues for such
Collaboration Product in compliance with the requirements of the U.S. Food, Drug
and Cosmetic Act, 21 USC Section 321 et seq., the regulations promulgated
thereunder, and the equivalent, laws, rules and regulations in the Territory and
shall promptly thereafter provide Amgen with a copy of such report.

      (c) On an indication-by-indication basis, after the Transition Date for a
Collaboration Product, the Commercial Lead shall be responsible (as the sponsor
and party of record) for reporting to Regulatory Authorities any adverse
experience and safety issues regarding such Collaboration Product in compliance
with the requirements of all applicable laws and regulations (including the FD&C
Act and the PHS Act, and any amendments thereto and the regulations promulgated
thereunder, and the equivalent laws, rules and regulations of other countries in
the Territory) and shall promptly thereafter provide the other Party with a copy
of such report. To the extent Hyseq is conducting clinical studies for a new
indication (after the Transition Date for such Collaboration Product in a
different indication), Hyseq shall provide Amgen (to the extent Amgen is the
Commercialization Lead) with a report of any related adverse events that need to
be reported to the Regulatory Authorities.

      4.7 COMMUNICATIONS.

      (a) The Regulatory Lead for an indication shall have exclusive
responsibility for all correspondence and for any official of communication
(except as the other Party may be required by applicable laws or regulations or
a Regulatory Authority to communicate) regarding such indication with applicable
Regulatory Authorities in the Territory and the other Party shall have the right
to be present (and to participate at the request of the Regulatory Lead or the
Regulatory Authority) at all face-to-face meetings and scheduled conference
calls regarding significant clinical events or decisions. If one Party is
required by applicable laws or regulations or a Regulatory Authority to disclose
information to such Regulatory Authority having jurisdiction in

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                                       8.
<PAGE>

the Territory, including information regarding the manufacture of Collaboration
Products, such Party will notify the other Party before communicating with the
Regulatory Authority.

      (b) After the Effective Date and prior to the Transition Date for a
Collaboration Product in an indication, and with respect to such indication,
Amgen (to the extent it is the Manufacturing Lead) will [***] where the
information is reasonably required for Hyseq to carry out its responsibilities
as Development Lead and/or Regulatory Lead and/or Commercial Lead, or is
required by law, rule, regulation or a Regulatory Authority having jurisdiction
in the Territory, to have access; [***]. For so long as Amgen is supplying Hyseq
with Collaboration Products hereunder, Amgen shall have the right to be present
at all meetings and to participate in telephone calls with Regulatory
Authorities having jurisdiction in the Territory wherein the CMC contained in
any Regulatory Filing is to be discussed.

      (c) After the Transition Date for a Collaboration Product in an
indication, and with respect to such indication, the Commercial Lead (as the
Regulatory Lead) shall have exclusive responsibility for all correspondence and
for any official communications (except as the other Party may be required by
applicable laws or regulations or a Regulatory Authority to communicate) with
Regulatory Authorities in the Territory (e.g., annual reports, filing of
Promotional Materials) consistent with all applicable laws and regulations
(including the FD&C Act and the PHS Act, and any amendments thereto and the
regulations promulgated thereunder) and the equivalent regulations of any
country in the Territory. The other Party shall have the right to be present
(and to participate at the request of the Commercial Lead or the Regulatory
Authority) at all face-to-face meetings and scheduled conference calls regarding
significant clinical events or decisions. Except as may be required by
applicable laws and regulations, or requested by the Commercial Lead or any
Regulatory Authority having jurisdiction in the Territory, the other Party shall
not communicate regarding any Collaboration Product with any Regulatory
Authority having jurisdiction in the Territory. The other Party shall keep the
Commercial Lead informed of any such required communications. The other Party
shall provide the Commercial Lead with all information regarding ongoing
activities (in clinical trials, etc.) that the Commercial Lead needs to fulfill
the reporting requirements to Regulatory Authorities for the Collaboration
Products.

      (d) Each Party shall promptly notify the other Party of and provide such
other Party with a copy of any correspondence or other reports or complaints
submitted to or received from any Regulatory Authority, or other Third Party
claiming that any Promotional Materials are inconsistent with the Product
Labeling or are otherwise in violation of any applicable laws and regulations
(including the FD&C Act, the PHS Act, and any amendments thereto and the
regulations promulgated thereunder) and the equivalent regulations in the
Territory.

      4.8 APPLICATIONS FOR REGULATORY EXCLUSIVITY. The Parties recognize that
exclusivity rights granted or provided for under regulatory laws of the
countries of the Territory may be commercially significant to Collaboration
Products. To the extent permitted by law, as between the Parties, the Commercial
Lead shall have the exclusive right to file for, request and maintain any
regulatory exclusivity rights for Collaboration Products in the Territory
(including without limitation regulatory exclusivity rights based upon an orphan
drug designation of a Collaboration Product) and to conduct and prosecute any
proceedings or actions to enforce such regulatory exclusivity rights.

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                                       9.
<PAGE>

      4.9 RECALLS.

      (a) The Parties shall exchange their internal standard operating
procedures, if any, as to product recalls ("SOPs") [***]after the Effective Date
and thereafter [***]after such SOPs are approved or modified. [***]. In all
other circumstances Recalls can only be made by [***]of the Steering Committee
and shall be made by the Party having the [***]a Recall pursuant to Section
4.9(b), below. The Steering Committee will meet (in person, by telephone or
otherwise) to discuss such other circumstances and to consider appropriate
courses of action, which courses of action with respect to a Recall shall be
consistent with the internal SOP of the Party having the [***]such Recall
pursuant to Section 4.9(b) below, and the other Party shall make available to
the Party having the [***] such Recall all pertinent records which the Party
having the [***]such Recall may reasonably request to assist in effecting any
Recall.

      (b) With respect to any clinical studies conducted by Hyseq under this
Agreement, Hyseq shall have the [***]a Recall of the Collaboration Product in
the Territory. If Hyseq shall elect not to conduct a Recall of the Collaboration
Product in the Territory when, in the good faith opinion of Amgen, regulatory
timeframes or public safety considerations so require, Amgen shall have the
right to conduct such Recall. Other than with respect to any clinical studies
conducted by Hyseq under this Agreement, the Commercial Lead shall have the
[***]any Recall of the Collaboration Product in the Territory. [***], the other
Party shall have the right to conduct such Recall. Hyseq and Amgen shall each
maintain complete and accurate records of any Recall it has the [***] pursuant
to this Section 4.9 for such periods as may be required by legal requirements,
but in any event for no less than [***].

      4.10 MANUFACTURING. The Manufacturing Lead shall cooperate with the
Regulatory Lead for a Collaboration Product in an indication with respect to
Regulatory Authority reporting, other communications and Regulatory Filings
regarding such Collaboration Product in such indication and the Manufacturing
Lead shall bear initial responsibility for preparing communications relating to
manufacturing issues, subject to review by the other Party. In order to help
preserve the proprietary nature of Amgen's manufacturing information (e.g., the
CMC section contained in any Regulatory Filings), [***]; provided however, that
Hyseq (as Development Lead, Regulatory Lead and/or Commercial Lead) [***] , to
the extent required by law, rule, regulation or a Regulatory Authority having
jurisdiction in the Territory or which Hyseq[***] in order to carry out its
responsibilities as Development Lead and/or Regulatory Lead and/or Commercial
Lead. [***].

                                    ARTICLE 5

                                COMMERCIALIZATION

      5.1 IDENTIFICATION OF COMMERCIAL LEAD AND CO-DETAILER. Unless Amgen elects
to exercise its option right to convert its Commercial Lead right to a
Co-Detailer right pursuant to Section 5.8, reference herein to "Commercial Lead"
shall mean Amgen and reference to "Co-Detailer" shall mean Hyseq. If Amgen
exercises its option pursuant to Section 5.8, reference to "Commercial Lead"
shall mean Hyseq and reference to "Co-Detailer" shall mean Amgen.

      5.2 RESPONSIBILITIES AND RIGHTS OF THE COMMERCIAL LEAD. The Commercial
Lead shall be responsible for preparing and submitting the Commercial Plan
section of the Program

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Plan to the Steering Committee (within [***]after the filing of a first BLA for
a first Collaboration Product for an indication) for its approval, as well as
updating the Commercial Plan [***]; provided however, it is acknowledged and
agreed that the Commercial Plan may need to be modified from time-to-time,
[***], upon the occurrence of unanticipated events. [***]. The Commercial Lead
shall have responsibility for all aspects of Commercializing Collaboration
Product(s) in the Territory, including making all strategic and tactical
decisions with respect thereto in accordance with the Commercial Plan and
establishing the methods and means by which it performs such services (including
the management of permitted subcontractors, pursuant to Section 18.7). Each
Party shall be responsible for carrying out its assigned activities in
accordance with the Commercial Plan. These activities shall include, without
limitation: (a) Commercial strategies (e.g., strategies for regulatory,
branding, product positioning, pre-launch (e.g., market research), launch and
post-launch marketing and promotion, pricing and reimbursement and field sales
force optimization); (b) packaging, labeling and language to be included in the
package insert; (c) forecasting sales and Commercial manufacturing production
requirements; (d) creating and developing Promotional Materials regarding
Collaboration Products which are intended for distribution to Third Parties
(including medical professionals) and to the Parties' respective sales forces;
(e) Promotion; (f) Detailing (subject to the Co-Detailer's limited right as set
forth in Section 5.3), including setting sales force staffing levels and
Detailing levels (including the relative proportion of required primary
Details); (g) sales and distribution including booking sales (i.e., recognizing
all revenues), taking orders and distributing, contracting, handling of returns,
handling all aspects of order processing, invoicing and collecting, warehousing,
documenting inventory and receivables and collecting prescription tracking, call
reporting, handling data regarding sales to hospitals and other end users (e.g.,
DDD data) and handling all other customer service-related functions); (h) level
of sampling; (i) selecting, obtaining and maintaining generic names and Product
Trademarks; (j) licensing or otherwise acquiring rights to intellectual property
from Third Parties (but excluding anything covered by Section 6.8); (k)
preparing and filing Drug Approval Applications for all clinical studies; (l)
supervising and training of (and coordinating sales briefing meetings and
disseminating information, including all communications related to marketing and
Promotion) and otherwise aligning sales force operations by and between sales
representatives of both Parties as may be required to Detail Collaboration
Products as provided herein; (m) establishing target call lists; (n) carrying
out all aspects of (e.g., designing studies and protocols) conducting, and
preparing the associated Regulatory Plan for all Post-Approval Clinical Studies;
(o) preparing publications and presentations of data regarding Collaboration
Products generated upon or after the Transition Date of the first Collaboration
Product and (p) establishing collaboration and material transfer agreements,
pursuant to Section 9.13, upon or after the Transition Date of the first
Collaboration Product.

      5.3 LIMITED CO-DETAILING RIGHTS OF CO-DETAILER.

      (a) At its request, the Co-Detailer shall have a limited secondary right,
but not the obligation, to deploy a supportive sales force in the United States
to co-Detail Collaboration Products, [***]. For the avoidance of doubt, in the
event the Co-Detailer elects not to deploy a supportive sales force, the
Co-Detailer shall retain its designation as "Co-Detailer" hereunder and its
rights and obligations will not otherwise be limited or restricted (including
the rights of a "Co-Detailer" under this Agreement); provided however that if
the Co-Detailer later elects to

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deploy a supportive sales force the Commercial Lead shall transition activities
to the Co-Detailer in an orderly manner that will not adversely affect product
sales or profitability of the Collaboration Products. All such co-Detailing
efforts by the Co-Detailer shall be under the coordination, direction and
approval of the Commercial Lead (after consultation with the Co-Detailer). Such
coordination, direction and approval shall include, without limitation, the
following terms and conditions.

            (i) The Co-Detailer's sales force shall only Detail a Collaboration
      Product [***].

            (ii) The Co-Detailer's sales force shall [***].

            (iii) The Co-Detailer's sales force shall jointly Detail with the
      sales force of the Commercial Lead under a single Product Trademark in
      accordance with the Commercial Plan including, without limitation, being
      trained by and using the field sales force materials (including, without
      limitation, Promotional Materials) and systems of the Commercial Lead.

            (iv) The Co-Detailer's sales force shall only Detail a Collaboration
      Product [***].

            (v) The number of representatives within the Co-Detailer's sales
      force shall be determined as follows:

                  (1) in any succeeding Calendar Year following a Calendar Year
            in which the U.S. annual Net Sales of Collaboration Products shall
            have been below or equal to [***], the number of representatives
            within the Co-Detailer's sales force for any such succeeding
            Calendar Year shall be approximately [***]of the estimated total
            number of representatives within the combined field sales force of
            both Parties, as set forth in such Commercial Plan; and

                  (2) in any succeeding Calendar Year following a Calendar Year
            in which the U.S. annual Net Sales of Collaboration Products shall
            have been above [***], the number of representatives within the
            Co-Detailer's sales force for any such succeeding Calendar Year
            shall be approximately [***]of the estimated total number of
            representatives within the combined field sales force of both
            Parties, as set forth in such Commercial Plan.

      (b) The Commercial Lead shall determine the minimum level of effort and
resources the Co-Detailer shall be directed to commit to individual field
activities under Section 5.3(a), provided the overall effort and resources of
the Co-Detailer shall be generally proportional to the relative percentage of
sales representatives deployed in the United States by the Co-Detailer under
Section 5.3(a)(v).

      (c) Except with the prior written consent of the Commercial Lead, all
sales representatives of the Co-Detailer Detailing a Collaboration Product shall
be [***].

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      (d) If a Collaboration Product is returned to the Co-Detailer, it shall
promptly be shipped to the facility responsible for shipment of Collaboration
Products in the country in question, to the attention of a department or to
another location as may be designated by the Commercial Lead.

      (e) Neither Party shall have any responsibility for the hiring, firing or
compensation of the other Party's employees or for any employee benefits. No
employee or representative of a Party shall have any authority to bind or
obligate the other Party to this Agreement for any sum or in any manner
whatsoever, or to create or impose any contractual or other liability on the
other Party without said other Party's authorized written approval.

      5.4 MEDICAL AND OTHER INQUIRIES. The Commercial Lead shall have
responsibility for all correspondence and communication with physicians and
other health care professionals and customers in the Territory regarding product
complaints (e.g., quality) and all adverse drug experience information and,
other than with respect to the Co-Detailer's rights in Section 5.3, all other
correspondence and communication with physicians and other health care
professionals and customers in the Territory. The Commercial Lead shall keep
such records and make such reports as shall be reasonably necessary to document
such communications in compliance with all applicable regulatory requirements.

      5.5 PROMOTIONAL MATERIALS. The Commercial Lead shall be responsible for
the creation, preparation, production and reproduction of all Promotional
Materials and for filing, as appropriate, such Promotional Materials with all
Regulatory Authorities.

      (a) Upon the other Party's request and to the extent permitted by law,
regulation or Regulatory Authorities, the other Party's corporate name and/or
logo shall be included on Promotional Materials and Product Labeling in
positions of equivalent prominence and frequency with the corporate name and
logo of the Commercial Lead.

      (b) In order to maintain the value of the other Party's corporate name
and/or logo, when using the other Party's corporate name and/or logo, the
Commercial Lead shall maintain such reasonable quality standards as it maintains
for its own corporate name and/or logo and shall comply with the other Party's
then-current policies regarding use of its corporate name and/or logo. Prior to
the use thereof, the Commercial Lead shall provide to the other Party a
prototype of any Promotional Materials or Product Labeling which contains the
other Party's corporate name and/or logo, so that the other Party may review the
manner in which its corporate name and/or logo are used therein. The other Party
shall notify the Commercial Lead within [***] after delivery of such prototype,
whether the other Party approves or disapproves of the manner of such use and,
in the case of disapproval, the specific reasons therefor and an acceptable
alternative. [***].

      5.6 COMPLIANCE WITH LAWS, REGULATIONS AND GUIDELINES. Each Party agrees to
comply with all applicable laws, rules and regulations (e.g., the FD&C Act, the
PHS Act, the U.S. Foreign Corrupt Practices Act and any amendments thereto and
the regulations promulgated thereunder, and the equivalent laws, rules and
regulations in the Territory) and in all material respects to conform its
practices and procedures with, as applicable, the Pharmaceutical Research and
Manufacturers of America ("PhRMA") Code of Pharmaceutical Marketing Practices
and the

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American Medical Association ("AMA") Guidelines on Gifts to Physicians from
Industry, as the same may be amended from time to time, and equivalent
guidelines in the Territory with respect to the Commercialization of
Collaboration Products. Each Party shall conduct its business operations and
cause each of its employees, representatives and agents to do nothing which such
Party knows or reasonably should know would jeopardize the good will or
reputation of the other Party or the Collaboration Products. Neither Party shall
be required to undertake any activity relating to the Commercialization of
Collaboration Products that it believes, in good faith, may violate any law or
regulations. Each Party shall promptly [***] notify the other Party of and
provide to that other Party a copy of any correspondence or other reports with
respect to the Promoting or Detailing of Collaboration Products submitted to or
received from PhRMA or the AMA or equivalent organizations in the Territory and
the Commercial Lead shall be responsible for responding to such correspondence
or other reports. Each Party shall in all material respects conform its
practices and procedures relating to educating the medical community in the U.S.
with respect to Collaboration Products to the Accreditation Council for
Continuing Medical Education ("ACCME") Standards for Commercial Support of
Continuing Medical Education and any applicable FDA regulations or guidelines,
as the same may be amended from time to time, and, as applicable, equivalent
guidelines in the Territory and each Party shall promptly notify the other Party
of and provide to the other Party a copy of any correspondence or other reports
submitted to or received from the ACCME with respect to Collaboration Products
and the Commercial Lead shall be responsible for responding to such
correspondence or other reports.

      5.7 REPORTS.

      (a) For information purposes each Party shall provide the other Party with
current Detailing reports of the number of Details delivered, broken down by
sales force and by physician specialty. Such Detailing reports and any other
relevant sales force information related to such Collaboration Product shall be
provided to the other Party on a mutually agreed regular basis (e.g., monthly).

      (b) No later than [***] after the conclusion of each Calendar Quarter
after First Commercial Sale of a Collaboration Product in a country in the
Territory, each Party shall submit to the other Party an audit report, based
upon the reporting Party's internal Detailing report data, setting forth the
number of the reporting Party's Details for such Collaboration Product for the
Calendar Quarter for each such country in the Territory, broken down by sales
force and by physician specialty. Each Party agrees to make available to the
other Party, upon reasonable advance notice, such books and records necessary to
verify the accuracy of such audit report in respect of any Calendar Quarter
ending not more than [***] prior to the date of such request. Upon expiration of
[***] following the end of any Calendar Year, the audit report reflecting the
reporting Party's Details for such Collaboration Product for such Calendar Year
shall be binding on the other Party, and the reporting Party shall be released
from any liability or accountability to the other Party with respect to the
number of Details given during such Calendar Year unless prior to such
expiration the other Party has notified the reporting Party of an issue
regarding such audit report (arising from such inspection) pursuant to Section
5.7(c), below.

      (c) Except as set forth in this Section 5.7 and subject to the other
Party's rights under Section 5.7(b), for purposes of this Agreement the number
of Details for a Collaboration Product

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performed by a Party for a given Calendar Quarter shall be based on such
performing Party's internal Detailing report data.

            (i) If the other Party has a good faith concern with the accuracy of
      the number of the performing Party's Details reflected by the performing
      Party's internal Detailing report data (based on the other Party's
      assessment of such data when compared to available Third Party audit data,
      sampling data, if applicable, or other relevant data relating to the
      performing Party's Detailing of such Collaboration Product), then the
      other Party shall so advise the performing Party of such concern, and
      promptly thereafter the other Party's and the performing Party's
      representatives shall consider in good faith whether the number of Details
      reflected by the performing Party's internal Detailing report data are
      accurate and, if not, whether an adjustment to the number of Details of
      such Collaboration Product performed by the performing Party for such
      Calendar Quarter is appropriate.

            (ii) If such representatives referred to in Section 5.7(c)(i) are
      unable to resolve the matter, either Party may, by notice to the other
      Party, have the dispute [***], or their designees, for attempted
      resolution by good faith negotiations for a period of not more than
      [***]after such notice is received or such other period of time as may be
      mutually agreed upon by the Parties to determine whether an adjustment to
      the number of the performing Party's Details for Collaboration Product in
      such Calendar Quarter is appropriate.

            (iii) If the Parties are unable to resolve the matter after such
      negotiation as provided in Section 5.7(c)(ii), then such dispute regarding
      the number of the performing Party's Details for Collaboration Product in
      such Calendar Quarter shall [***]. The fees that such market research firm
      or other expert shall be paid in connection with such resolution shall be
      charged to the Operating Profit or Loss account. The settlement of such
      dispute [***] shall be binding upon the Parties, and [***]). The Parties
      expressly recognize that Third Party audits of Details conducted hereunder
      do not accurately reflect actual Details conducted hereunder and that, for
      purposes of determining any potential shortfall in Details conducted
      hereunder, if the ratio of Third Party audits of Details conducted
      hereunder to the performing Party's internal Detail reports is within the
      range then existing for other comparably promoted products by the
      performing Party, then the performing Party's internal Details report
      shall be deemed to be accurate by the Parties.

      5.8 AMGEN'S CO-DETAILER OPTION.

      (a) Subject to the terms of this Section 5.8(a), Amgen shall have the
option to convert its right to be the Commercial Lead to the right to be the
Co-Detailer with respect to a Collaboration Product. Amgen may exercise such
option with respect to a Collaboration Product: (i) [***]. If Amgen wishes to
exercise such Co-Detailer option at the times permitted hereunder, it shall give
Hyseq written notice.

      (b) If Hyseq becomes the Commercial Lead of a Collaboration Product under
the terms and conditions of this Agreement, Amgen: (i) shall immediately and,
for a period of [***]

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after Hyseq's acceptance, provide reasonable assistance (including providing
reasonable access to and assistance from those of Amgen's Collaboration Product
marketing personnel selected by Amgen) to transition such marketing and sales
force training knowledge and materials to Hyseq to enable it to assume the
responsibilities of Commercial Lead pursuant to Section 5.2, provided however,
that Amgen shall retain its rights and obligations of Commercialization during
such [***] transition period; and (ii) shall assign Amgen's entire right, title
and interest in and to all Drug Approval Applications and, to the extent
applicable, Regulatory Approvals for Collaboration Products in the Territory to
Hyseq and, within such [***] period shall notify Regulatory Authorities in the
Territory of (and [***] thereafter, take all actions reasonably necessary to
effect or evidence) the transfer of such Drug Approval Applications and
Regulatory Approvals to Hyseq; [***]. Hyseq shall only be entitled to use such
information to the extent required by such law, rule, regulation or Regulatory
Authority or to the extent reasonably required to carry out its responsibilities
as Development, Regulatory and/or Commercial Lead. After such [***] period Hyseq
shall be the designated Commercial Lead and shall assume all rights and
obligations associated therewith as set forth in this Article 5, Amgen shall be
the Co-Detailer and shall assume all rights and obligations associated therewith
as set forth in this Article 5, and Hyseq shall be designated the Regulatory
Lead for the indications for which Amgen (as the Commercial Lead) had been the
Regulatory Lead and Hyseq shall assume all rights and obligations associated
therewith as set forth in Article 4.

                                    ARTICLE 6
                             MANUFACTURE AND SUPPLY

      6.1 MANUFACTURING LEAD. Reference to "Manufacturing Lead" shall mean
Amgen, unless Amgen elects to exercise its right pursuant to Section 6.7 below.
If Hyseq or a Third Party shall manufacture Collaboration Products then the
Manufacturing Lead shall be Hyseq.

      6.2 RESPONSIBILITIES AND RIGHTS OF MANUFACTURING LEAD. The Manufacturing
Lead shall be responsible for preparing and submitting the Process
Development/Manufacturing Plan section of the Program Plan to the Steering
Committee (within [***] after receiving annual forecasts from the Development
Lead and/or Commercial Lead, as applicable) for its approval, as well as
updating the Process Development/Manufacturing Plan [***]; provided however, it
is acknowledged and agreed that the Process Development/Manufacturing Plan may
need to be modified from time-to-time, between annual updates, upon the
occurrence of unanticipated events. The Manufacturing Lead shall have the first
right to manufacture and supply Collaboration Products for Development and
Commercialization in the Territory, in accordance with the Process
Development/Manufacturing Plan. The Process Development/Manufacturing Plan shall
set forth the activities necessary or useful to obtain the authorization to
manufacture, formulate, fill and ship Collaboration Products in the Territory
including, without limitation, bulk manufacture, finish and fill, labeling and
packaging, lot release and process development work to support quality
assurance, improving manufacturing/cost efficiency and commercial scale-up
manufacturing. [***] The Manufacturing Lead shall have responsibility for all
aspects of manufacturing Collaboration Products(s) in the Territory (excluding
product specifications and product forecasts), including making all strategic
and tactical decisions with respect thereto in accordance with the Process
Development/Manufacturing Plan, establishing the methods and means by which it
performs such services and fulfilling its regulatory responsibilities over all

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steps of the manufacturing process (including the management of permitted
subcontractors, pursuant to Section 18.7).

      6.3 MANUFACTURE OF COLLABORATION PRODUCTS FOR DEVELOPMENT. With respect to
each Collaboration Product selected to be advanced to IND-enabling toxicology
studies and/or clinical studies, prior to the first Transition Date with respect
to such Collaboration Product the Manufacturing Lead shall use [***] to develop
and initiate scale-up of the manufacturing process, to develop a manufacturing
process(es) suitable for commercial production, and to supply (in accordance
with Section 6.5) clinical grade, filled and finished, selected Collaboration
Products and placebo for use in all pre-clinical trials and clinical trials in
the Territory, in quantities (as reasonably forecast by Hyseq) and with
specifications (to the extent consistent with Section 6.5) as set forth in the
Process Development/Manufacturing Plan section of the Program Plan. The
Development Lead shall determine its good faith projected Collaboration Product
supply needs, taking into consideration inventory levels, and will deliver an
annual forecast, updated quarterly.

      6.4 MANUFACTURE OF COLLABORATION PRODUCT(s) FOR COMMERCIALIZATION. With
respect to each Collaboration Product, after the first Transition Date of each
such Collaboration Product the Manufacturing Lead shall use [***] to supply (in
accordance with Section 6.5) filled and finished Collaboration Products approved
by each applicable Regulatory Authority for commercial use in the Territory, in
quantities (as reasonably forecast by the Commercial Lead) and with
specifications (to the extent consistent with Section 6.5) as set forth in the
Process Development/Manufacturing Plan section of the Program Plan for such
approved Collaboration Product. The Commercial Lead shall determine its good
faith projected Collaboration Product supply needs, taking into consideration
inventory levels, and will deliver an annual rolling forecast, updated
quarterly.

      6.5 STANDARDS OF SUPPLY. Collaboration Products shall be manufactured by
the Manufacturing Lead (pursuant to Section 6.3 and 6.4) in accordance with
current GMP in a manufacturing process and facility as described in the
applicable Regulatory Filings filed with the Regulatory Authority. The
Manufacturing Lead shall be responsible for the labeling, packaging and lot
release of such Collaboration Products. The Manufacturing Lead shall be
responsible for the quality assurance/quality control (QA/QC) of all
manufactured Collaboration Products and shall provide a certification that all
supplied Collaboration Products shall conform to the product specifications.

      6.6 STANDARD COST AND BUDGET. The Manufacturing Lead shall have the right
to charge to the Operating Profit or Loss account the cost of developing
manufacturing processes, manufacturing and supplying Collaboration Products in
accordance with Sections 6.3 and 6.4, at the Manufacturing Lead's Standard Cost
plus [***]. Standard Cost for a Calendar Year shall be estimated or established
on a reasonable basis by the Manufacturing Lead. Within [***] following the end
of the Manufacturing Lead's fiscal year, the Manufacturing Lead shall calculate
an annual adjustment by [***]. The Manufacturing Lead shall use this annual
adjustment to increase/decrease the Standard Cost for the then-current Calendar
Year in order to recover/refund this difference from/to the Parties. The per
unit annual adjustment to the Standard Cost shall be based upon [***]. Until the
annual adjustment is calculated, the Manufacturing Lead shall estimate the
annual adjustment to be included in the following year's Standard Cost in good
faith. [***] The

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Manufacturing Lead will give the other Party [***] written notice prior to
applying the [***] in Standard Cost. [***] per year, the other Party shall have
the right, at its own cost, to cause its independent certified public accountant
to audit the Manufacturing Lead's books and records, upon reasonable notice and
during normal business hours, to determine the accuracy of such Standard Cost
calculation and any adjustments thereto. In the event the manufacturing rights
are transferred to a Third Party manufacturer as per Section 6.7, the actual
cost of purchasing the Collaboration Product will be charged to the Operating
Profit or Loss account in lieu of charging the Manufacturing Lead's Standard
Cost plus [***] as outlined above.

      6.7 ALTERNATIVE MANUFACTURING SOURCE. In the event Amgen, at any time and
in its sole discretion, decides not to manufacture Collaboration Products and
not to act as the Manufacturing Lead as set forth in Section 6.3 or 6.4, then
Amgen shall provide written notice thereof to Hyseq. Within [***] after receipt
of such notice together with access to such Amgen Material and Manufacturing
Information reasonably necessary to make a decision on manufacturing, Hyseq
shall notify Amgen whether Hyseq shall manufacture Collaboration Products itself
or, if Hyseq does not elect to so manufacture, the name of a proposed Third
Party manufacturer for Amgen's approval, such approval not to be unreasonably
withheld; provided however, if Hyseq does not provide such notice within such
[***] period or if Amgen does not approve of a Third Party manufacturer in such
[***] period, Amgen [***] may, at any time thereafter, [***] select a Third
Party manufacturer which must [***] (within a [***] period of time thereafter)
to make Collaboration Products in a [***], such selection to be [***] Hyseq.
Once Amgen has approved [***] a Third Party manufacturer, Hyseq, in consultation
with Amgen, shall be responsible for [***] negotiating the terms of the
agreement pursuant to which such Third Party manufacturer will manufacture and
supply Collaboration Products, which agreement Amgen shall have the right to
approve, such approval not to be unreasonably withheld or delayed. [***] The
Parties acknowledge that Amgen has a license from [***] for licensing of certain
[***] technology. Amgen agrees to contact [***] after the Effective Date to
request a [***] right of sublicense to Hyseq of Amgen's rights under such
license with respect to Collaboration Products; provided however, Hyseq shall
have the right to approve of any such sublicense and agrees that (i) [***] and
(ii) nothing contained hereunder shall be construed as a representation that any
such sublicense will be available or as a commitment by Amgen that Hyseq may
obtain such sublicense as a result of Amgen's effort. Thereafter, Hyseq shall be
designated as the "Manufacturing Lead" (whether it manufactures Collaboration
Products itself or via an approved Third Party manufacturer) and shall assume
all rights and obligations therewith as set forth in this Article 6. [***] after
receiving notice from Hyseq that it shall manufacture Collaboration Products or
after Amgen's approval of a Third Party manufacturer under this Section 6.7,
Amgen shall transfer to Hyseq (or an approved Third Party manufacturer as
designated in such notice) the Amgen Material and Manufacturing Information and
shall provide all associated technical assistance so as to permit the transferee
to implement the manufacturing process and shall grant to such transferee a
license under Amgen Technology to make (and in the case of Hyseq, to make and
have made) the Collaboration Products. All transfer of such Information and
Materials to Hyseq and associated assistance shall be. [***] after Hyseq
provides Amgen with notice that Hyseq shall manufacture Collaboration Products
or after Amgen's approval of a Third Party manufacturer under this Section 6.7,
Amgen will continue to provide clinical and commercial manufacturing of
then-manufactured Collaboration Products (or will provide an equivalent supply
to satisfy the then-current forecasts). The transfer of Amgen Material and
Manufacturing Information and

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continued supply of Collaboration Products by Amgen pursuant to this Section 6.7
shall be conducted in accordance with a transition plan which shall be approved
by [***] of the Steering Committee and which sets forth responsibilities and
schedules for transferring the Amgen Material and Manufacturing Information as
expeditiously as possible [***] with the goal of providing for an uninterrupted
supply of Collaboration Product of suitable quality and quantity required for
the Development and/or Commercialization to proceed. Once Amgen has transferred
the Amgen Materials and Manufacturing Information and otherwise fulfilled its
obligations under this Section 6.7, Amgen shall no longer be responsible for
manufacturing Collaboration Products under this Agreement.

      6.8 THIRD PARTY LICENSES. [***] deems necessary for a license or other
rights or to incur an obligation for any Third Party payments for a license to
any Third Party of Patent Rights and other intellectual property rights
necessary or useful to make or have made a Collaboration Product in a country in
the Territory, for subsequent use, sale or other exploitation or transfer of
physical possession of or title in a Collaboration Product in the Territory. The
Manufacturing Lead shall have the right to incorporate Third Party payments made
to any Third Party within the Cost of Goods, as set forth in Schedule I.

                                    ARTICLE 7
                           COLLABORATION CONSIDERATION

      7.1 LICENSE FEE. In lieu of the payment of up-front cash consideration and
subject to the terms and conditions set forth below and in that certain warrant
agreement executed on the same date herewith ("Warrant Purchase Agreement"),
Hyseq shall issue to Amgen an irrevocable warrant to purchase one million four
hundred ninety-one thousand five hundred forty-four (1,491,544) fully paid and
nonassessable shares of Hyseq's Common Stock, par value $ 0.001 per share, all
as more fully described in the Warrant Purchase Agreement. A copy of the Warrant
Purchase Agreement, in the form to be executed and delivered by each of Amgen
and Hyseq on the Effective Date, is attached hereto as Schedule III.

      7.2 REGULATORY APPROVAL MILESTONE. Hyseq shall pay to Amgen a one-time
milestone payment of [***]. Such Milestone Payment shall not be payable more
than once, no matter how many times achieved by one or more Collaboration
Product(s). Such Milestone Payments shall be nonrefundable and noncreditable
against any other fees or other payments due Amgen with respect to Collaboration
Products under this Agreement.

                                    ARTICLE 8
                     PROGRAM PLAN; OPERATING PROFIT OR LOSS

      8.1 PROGRAM PLAN.

      (a) No later than [***]after the Effective Date, the Steering Committee
shall review and approve the Program Plan (and associated budget) to cover the
first twelve (12) months after the Effective Date. Any disputes with respect to
the Program Plan shall be handled in accordance with Section 2.4(b). Once
approved, the Parties will be authorized to undertake their respective
activities for such initial twelve (12) month period under the Program Plan and
to

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charge the Operating Profit or Loss account for approved Collaboration
Expenditures. Schedule II provides a format for the Program Plan budget, which
format the Steering Committee shall have the right to modify from time-to-time.

      (b) Within [***] of the Effective Date and thereafter no later than [***]
before each anniversary of such [***] date of the Effective Date, the Steering
Committee shall review and approve the Program Plan (and associated budget)
covering the following Calendar Year. The Steering Committee shall determine the
timing of the annual budget cycles to meet the business objectives of both
Parties (e.g., to coincide with each Party's fiscal year) and will alter the
schedule accordingly. Once approved, the Parties will be authorized to undertake
their respective activities for such Calendar Year under the Program Plan and to
charge the Operating Profit or Loss account for approved Collaboration
Expenditures.

      (c) On a [***] basis the Steering Committee shall review the Collaboration
Expenditures actually incurred against the budget of the Program Plan for such
expenses in the applicable Calendar Year and consider for approval any
appropriate changes to such budget. In preparing the reports contemplated by
Sections 8.3- below, costs and expenses shall be submitted as part of
Collaboration Expenditures only to the extent made or incurred in conjunction
with an approved budget line item as approved and revised from time-to-time by
the Steering Committee. Any expenditure(s) not included in an approved Program
Plan and/or any acceptable cost overruns to the budget (as pre-determined by the
Steering Committee) shall need written approval by the Steering Committee prior
to being charged as Collaboration Expenditures to the Operating Profit or Loss
account. Any expenditures not otherwise approved by the Steering Committee shall
not be deemed Collaboration Expenditures and shall be completely assumed by the
Party assuming such expenditure. Any disputes regarding such expenditures shall
be handled in accordance with Section 2.4(b).

      8.2 OPERATING PROFIT OR LOSS SHARING. Amgen and Hyseq shall each share on
a fifty:fifty (50:50) basis the Operating Profit or Loss for all Collaboration
Products, except as set forth below:

      (a) As of the Effective Date, Hyseq shall be responsible for [***] of all
approved Collaboration Expenditures up to and including the first [***]incurred
after the Effective Date.

      (b) The Parties shall share on a fifty:fifty (50:50) basis all
Collaboration Expenditures in excess of [***] incurred after the Effective Date.

      8.3 ACCOUNTING AND REPORTING OF COLLABORATION PROFITS AND LOSSES.

      (a) On a quarterly basis during the Term of this Agreement, the Parties
shall each submit to the other Party a written report (including supporting
documentation) setting forth in reasonable detail an accounting of any approved
Collaboration Expenditures that have been incurred. These expenses will be
submitted in a timely manner to maintain accurate accounting of Operating Profit
or Loss.

      (b) Prior to the Transition Date of the first Collaboration Product, Hyseq
shall establish and maintain an accounting of the approved Collaboration
Expenditures in the

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Operating Profit or Loss account. The format of the reporting shall be initially
as proposed in Schedule II, which may be changed from time-to-time by the
Steering Committee to meet the business objectives of both Parties (e.g., to
coincide with each Party's fiscal year).

            (i) Prior to the Operating Profit or Loss account reaching or
      equaling a cumulative amount of [***] in Collaboration Expenditures from
      the Effective Date, Hyseq shall provide a [***] reporting of those
      Collaboration Expenditures to the Parties setting forth in reasonable
      detail (and including supporting documentation) an accounting of all items
      credited or charged to the Operating Profit or Loss account.

            (ii) After the Operating Profit or Loss account balance exceeds a
      cumulative amount of [***] in Collaboration Expenditures from the
      Effective Date, Hyseq shall provide a [***] reporting of those
      Collaboration Expenditures to the Parties. Within [***] following the end
      of each Calendar Quarter, Hyseq shall submit to Amgen a written report
      (including supporting documentation) setting forth in reasonable detail
      (and including supporting documentation) an accounting of all items
      credited or charged to the Operating Profit or Loss account and the
      calculation of any net amount owed by Hyseq to Amgen or by Amgen to Hyseq,
      as the case may be, in order to ensure the appropriate fifty-fifty (50:50)
      sharing of Operating Profit or Loss. The net amount payable shall be paid
      by Amgen or Hyseq, as the case may be, within [***] after receipt of such
      written report, without regard to any dispute as to the amounts under this
      Section 8.3(b)(ii), but subject to Section 18.17.

      (c) After the Transition Date of the first Collaboration Product, the
Commercial Lead shall establish and maintain an accounting of the approved
Collaboration Expenditures in the Operating Profit or Loss account. The format
of the reporting shall be initially as proposed in Schedule II, which may be
changed from time-to-time by the Steering Committee to meet the business
objectives of both Parties (e.g.,, to coincide with each Party's fiscal year).
Within [***] following the end of each Calendar Quarter, the Commercial Lead
shall submit to the other Party a written report setting forth in reasonable
detail (and including supporting documentation) an accounting of all items
credited or charged to the Operating Profit or Loss account and the calculation
of any net amount owed by Hyseq to Amgen or by Amgen to Hyseq, as the case may
be, in order to ensure the appropriate fifty-fifty (50:50) sharing of Operating
Profit or Loss. The net amount payable shall be paid by Amgen or Hyseq, as the
case may be, within [***] after receipt of such written report, without regard
to any dispute as to the amounts under this Section 8.3(c), but subject to
Section 18.17.

      (d) In the event of a dispute with respect to any amounts under Sections
8.3(b) or 8.3(c), the disputing Party shall provide written notice within [***]
after receipt of the written report in question, specifying such dispute and
explaining the basis of the dispute. The Parties shall promptly thereafter meet
and negotiate in good faith a resolution to such dispute. In the event that the
Parties are unable to resolve such dispute within [***] after notice by the
disputing Party, the matter shall be resolved in a manner consistent with the
procedures set forth in Article 17 and shall not be subject to either Party's
casting vote. Notwithstanding the above, such dispute resolution shall not
prejudice a Party's right to audit the records of the other Party in accordance
with Section 10.2.

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      (e) Hyseq and Amgen shall work in good faith to realize the benefits of
the orphan drug credits pursuant to IRC Section 41 and Section 45C for the
activities or expenditures of either Party under this Agreement or any legal
entity formed pursuant to Section 13.3(d).

      (f) Upon termination of this Agreement, the Parties shall immediately (but
in no event any later than [***] from such termination) conduct a final
accounting to reconcile, settle and close the Profit or Loss account; provided
however, that after such final accounting, with respect to surviving sections
that reference the charging or crediting of the Profit or Loss account (e.g.,
Section 14.3, Section 16.9(a)(i) as it applies to Section 9.7(c) and Section
16.9(b)(i) as it applies to Sections 9.6(d) and Section 9.7(c)), such charges or
credits shall be made directly between the Parties and shall proportionally
borne by the Parties in the same manner as if such Profit or Loss account was
still open].

                                    ARTICLE 9
                              INTELLECTUAL PROPERTY

      9.1 TECHNOLOGY OWNERSHIP. Ownership of inventions shall be determined in
accordance with the rules of inventorship under United States patent laws.
Subject to the licenses granted in Section 9.2(a) below, as between the Parties,
Amgen shall own all right, title and interest in and to Amgen Technology, and
any Confidential Information contained therein shall be considered the
Confidential Information of Amgen. Subject to the licenses granted in Section
9.2(b) below, as between the Parties, Hyseq shall own all right, title and
interest in and to Hyseq Technology, and any Confidential Information contained
therein shall be considered the Confidential Information of Hyseq. All right,
title and interest in and to Joint Know-How (which shall be considered the joint
Confidential Information of the Parties) and Joint Patent Rights shall be owned,
as between the Parties, jointly by Hyseq and Amgen. Other than with respect to
the rights and licenses granted under this Agreement to Joint Know-How, each
Party shall have the unrestricted, royalty-free, worldwide right to make, have
made, use, sell, lease, offer to sell or lease, import, export or otherwise
exploit, or transfer physical possession of or title in Joint Know-How, without
accounting. All right and interest in and to Product Trademarks shall be owned,
as between the Parties, jointly by Hyseq and Amgen, and any Confidential
Information related thereto shall be considered the joint Confidential
Information of the Parties; provided however, if for any reason the Parties are
prohibited by law, rule or regulation in any country from jointly owning Product
Trademarks (or if the mutually acceptable outside counsel retained pursuant to
Section 9.4(d) so advises) the Commercial Lead shall own all such Product
Trademarks.

      9.2 PATENT LICENSES.

      (a) Amgen hereby grants to Hyseq a sole royalty-free license (co-exclusive
with only Amgen), with a qualified right to sublicense pursuant to this Section
9.2(a), under the Amgen Technology to use, sell, offer to sell, import, export
or otherwise transfer physical possession of or otherwise transfer title in
Collaboration Products in the Field of Use in the Territory, solely in
compliance with the terms and conditions of this Agreement. For the avoidance of
doubt, as used in this Agreement a "sole" license which is "co-exclusive" with
only the licensor means that only the licensor and the licensee shall enjoy the
rights to the technology so licensed, to the

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exclusion of all others. Pursuant to Sections 18.6 and 18.7 below, Hyseq may
grant sublicenses (or covenants not to sue) under Hyseq Technology, Joint
Know-How, Joint Patent Rights and, to the extent licensed under this Section
9.2(a), Amgen Technology.

      (b) Hyseq hereby grants to Amgen a sole royalty-free license (co-exclusive
with only Hyseq), with a qualified right to sublicense pursuant to this Section
9.2(b), under the Hyseq Technology to make, have made, use, sell, offer to sell,
import, export or otherwise transfer physical possession of or otherwise
transfer title in Collaboration Products in the Field of Use in the Territory,
solely in compliance with the terms and conditions of this Agreement. Pursuant
to Sections 18.6 and 18.7 below, Amgen may grant sublicenses (or covenants not
to sue) under Amgen Technology, Joint Know-How, Joint Patent Rights and, to the
extent licensed under this Section 9.2(b), Hyseq Technology.

      (c) Pursuant to Section 6.7 and subject to this Section 9.2(c) and Section
9.2(e) below, Amgen shall grant to Hyseq an exclusive license (with a limited
sublicense right to Third Party manufacturers approved by Amgen) under Amgen
Technology and Amgen Material and Manufacturing Information to make, have made
and use Collaboration Products solely in compliance with the terms and
conditions of this Agreement. Amgen expressly reserves for itself and its
Affiliates a non-transferable, non-sublicensable license under the Amgen
Technology and the Amgen Material and Manufacturing Information to make and use
(but not to transfer, sell, lease, offer to sell or lease, or otherwise transfer
title to or interest in) Collaboration Products for its (and its Affiliates')
own internal non-commercial purposes only. Amgen shall further retain all rights
in Amgen Technology and Amgen Material and Information not expressly licensed
hereunder (e.g., to make, have made, use, sell, offer to sell, import, export or
otherwise transfer physical possession of or otherwise transfer title in
products, other than Collaboration Products, in the Field of Use in the
Territory).

      (d) Other than as expressly set forth in this Section 9.2, neither Party
shall grant any sublicense without the prior written consent of the other Party.

      (e) Certain license rights granted to a Party under this Section 9.2 may
include a sublicense of Patent Rights and know-how of Third Parties under Third
Party licenses. Notwithstanding anything to the contrary in this Agreement, the
Party receiving a sublicense of such Third Party licenses shall, in exercising
such sublicense rights, comply with, perform in accordance with, and be subject
to the provisions of such Third Party licenses relating to Collaboration
Products if the granting Party has provided a copy of such Third Party license
to the Party receiving a sublicense of such Third Party licenses. Each Party
shall promptly provide to the other Party a copy of any notice of breach
received by it under any such Third Party license.

      9.3 TRADEMARK; COPYRIGHT LICENSES.

      (a) Amgen hereby grants to Hyseq a sole royalty-free license (co-exclusive
with only Amgen), without the right to grant sublicenses (except as set forth in
Sections 18.6 and 18.7), under Amgen Trademarks and Amgen's entire right, title
and interest in and to Product Trademarks to use and display the Amgen
Trademarks and Product Trademarks in connection

                                      23.
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with Collaboration Products in the Territory solely in compliance with the terms
and conditions of this Agreement (including Section 5.5); provided however, that
Hyseq agrees to comply with Amgen's then-current trademark policy. Amgen shall
have the right to audit and inspect, upon advance written notice and during
regular business hours, Hyseq's use of Trademarks licensed hereunder.

      (b) Hyseq hereby grants to Amgen a sole royalty-free license (co-exclusive
with only Hyseq), without the right to grant sublicenses (except as set forth in
Sections 18.6 and 18.7), under Hyseq Trademarks and Hyseq's entire right, title
and interest in and to Product Trademarks to use and display the Hyseq
Trademarks and Product Trademarks in connection with Collaboration Products in
the Territory solely in compliance with the terms and conditions of this
Agreement (including Section 5.5); provided however, that Amgen agrees to comply
with Hyseq's then-current trademark policy. Hyseq shall have the right to audit
and inspect, upon advance written notice and during regular business hours,
Amgen's use of Trademarks licensed hereunder.

      (c) Each Party hereby grants to the other Party a sole license
(co-exclusive with only the other Party) under the Party's entire right, title
and interest in any copyrights in Promotional Materials, without the right to
grant sublicenses (except as set forth in Sections 18.6 and 18.7), to reproduce,
distribute copies of, prepare derivative works of and publicly perform and
display such Promotional Materials in connection with Collaboration Products in
the Territory solely in compliance with the terms and conditions of this
Agreement (including Section 5.5).

      9.4 PROSECUTION.

      (a) (i) Amgen shall be responsible (using mutually acceptable outside
      counsel) for the filing, prosecution, defense and maintenance of the Amgen
      Patent Rights and Joint Patent Rights before all patent authorities in the
      Territory.

            (ii) [***] such filing, prosecution and defense by Amgen of the
      Amgen Patent Rights and Joint Patent Rights and [***] Amgen shall propose
      [***]. To that end, Amgen shall instruct such outside counsel to furnish
      Hyseq with a reasonably complete draft of each submission to a patent
      authority regarding Amgen Patent Rights and Joint Patent Rights no later
      than [***] prior to the date such submission is proposed to be made, or if
      given less than [***] to respond as soon as practicable, and Amgen [***]
      thereon. Additionally, Amgen shall instruct such outside counsel to
      provide Hyseq with a copy of each submission made to and document received
      from a patent authority regarding any Amgen Patent Rights and Joint Patent
      Rights [***] after making such filing or receiving such document. If Amgen
      determines in its sole discretion to not file, prosecute, defend or
      maintain any claim or patent application or patent within Amgen Patent
      Rights and Joint Patent Rights in any country, then Amgen shall provide
      Hyseq with [***] prior written notice of such determination and shall
      provide Hyseq with the right and opportunity to file, prosecute, defend
      and maintain such claim or patent application or patent on behalf of
      Amgen.

      (b) (i) Hyseq shall be responsible (using mutually acceptable outside
      counsel which, unless there is a conflict of interest, shall be the
      mutually acceptable outside

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      counsel handling Amgen Patent Rights and Joint Patent Rights pursuant to
      Section 9.4(a)) for the filing, prosecution, defense and maintenance of
      Hyseq Patent Rights before all patent authorities in the Territory.

            (ii) [***] such filing, prosecution and defense by Hyseq of the
      Hyseq Patent Rights and [***] Hyseq shall [***]. To that end, Hyseq shall
      instruct such outside counsel to furnish Amgen with a reasonably complete
      draft of each submission to a patent authority regarding Hyseq Patent
      Rights no later than [***] prior to the date such submission is proposed
      to be made, or if given less than [***] to respond as soon as practicable,
      and Hyseq [***] thereon. Additionally, Hyseq shall instruct such outside
      counsel to provide Amgen with a copy of each submission made to and
      document received from a patent authority regarding any Hyseq Patent
      Rights [***] after making such filing or receiving such document. If Hyseq
      determines in its sole discretion to not file, prosecute, defend or
      maintain any claim or patent application or patent within the Hyseq Patent
      Rights in any country, then Hyseq shall provide Amgen with [***] prior
      written notice of such determination and shall provide Amgen with the
      right and opportunity to file, prosecute, defend and maintain such claim
      or patent application or patent on behalf of Hyseq.

      (c) Amgen and Hyseq shall each provide to the other any invention
disclosures submitted to its respective outside or in-house patent counsel in
the normal course of its business which disclose an invention within Amgen
Know-How, Hyseq Know-How or Joint Know-How, respectively. Amgen and Hyseq shall
cooperate with each other and render all reasonable assistance in prosecuting
and maintaining all intellectual property licensed under this Agreement. Both
Parties shall meet regularly, but not less than on a quarterly basis, to discuss
the prosecution (and other related proceedings, such as interferences and
oppositions) of all intellectual property licensed under this Agreement. Amgen
and Hyseq shall cooperate with each other in any such matters, and shall sign
any necessary legal papers and provide the Party responsible for such
prosecution with data or other information in support thereof (and use their
[***] to ensure the cooperation of any of their respective personnel, Affiliates
and licensee(s) as might reasonably be requested).

      (d) The Commercial Lead shall be responsible (using mutually acceptable
outside counsel) for the filing, prosecution, defense and maintenance of the
Product Trademarks before all trademark authorities in the Territory. [***] such
filing, prosecution and defense of the Product Trademarks by the Commercial Lead
and [***] the Commercial Lead shall [***]. To that end, the Commercial Lead
shall instruct such outside counsel to furnish the other Party with a reasonably
complete draft of each submission to a trademark authority regarding the Product
Trademarks no later than [***] prior to the date such submission is proposed to
be made, or if given less than [***] to respond as soon as practicable, and the
Commercial Lead [***] thereon. Additionally, the Commercial Lead shall instruct
such outside counsel to provide the other Party with a copy of each submission
made to or document received from a trademark authority regarding any Product
Trademarks [***] after making such filing or receiving such document. If the
Commercial Lead determines in its sole discretion to not file, prosecute, defend
or maintain a Product Trademark in any country, then the Commercial Lead shall
provide the other Party with

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[***] prior written notice of such determination and shall provide the other
Party with the right and opportunity to file, prosecute, defend and maintain
such Product Trademark on behalf of the Commercial Lead.

      9.5 PATENT AND TRADEMARK EXPENSES.

      (a) With respect to carrying out its responsibilities under Section 9.4,
Amgen shall have the right to charge the Operating Profit or Loss account for
all of Amgen's external costs, expenses and fees (as documented by written
invoices for legal services and receipts for filing, maintenance and other fees
paid) to have outside counsel prepare, file, ex parte prosecute and maintain
and/or defend Amgen Patent Rights, Joint Patent Rights and, if applicable,
Product Trademarks before all patent and trademark offices in the Territory
during the Term. Amgen shall obtain advance written consent from Hyseq (such
consent not to be unreasonably withheld) in the event any such ex parte expenses
collectively exceed [***] in any given Calendar Year; provided however, that the
costs, expenses and fees to defend such Patent Rights in any inter partes
actions before any such patent offices (including, without limitation,
interferences and oppositions) shall be excluded from such [***]. In the event
Hyseq does not consent to reimburse Amgen for such costs, expenses or fees in
excess of such [***] in a Calendar Year for any aspect related to preparing,
filing, ex parte prosecuting, maintaining or defending any of the Amgen Patent
Rights, Joint Patent Rights and Product Trademarks in the Territory during the
Term, Amgen shall not be obligated to continue any of its activities or to incur
any further costs or expenses related to such aspect.

      (b) With respect to carrying out its responsibilities under Section 9.4,
Hyseq shall have the right to charge the Operating Profit or Loss account for
all of Hyseq's external costs, expenses and fees (as documented by written
invoices for legal services and receipts for filing, maintenance and other fees
paid) to have outside counsel prepare, file, ex parte prosecute and maintain,
and/or defend Hyseq Patent Rights, any Amgen Patent Rights and Joint Patent
Rights (to the extent not pursued by Amgen) and, if applicable, Product
Trademarks before all patent and trademark offices in the Territory during the
Term. Hyseq shall obtain advance written consent from Amgen (such consent not to
be unreasonably withheld) in the event any such ex parte costs, expenses and
fees collectively exceed [***] in any given Calendar Year; provided however,
that the costs, expenses and fees to defend such Patent Rights in any inter
partes actions before any such patent offices (including, without limitation,
interferences and oppositions) shall be excluded from such [***]. In the event
Amgen does not consent to reimburse Hyseq for such costs, expenses or fees in
excess of such [***] in a Calendar Year for any aspect related to preparing,
filing, ex parte prosecuting, maintaining or defending any of the Hyseq Patent
Rights, any Amgen Patent Rights and Joint Patent Rights (to the extent not
pursued by Amgen), and Product Trademarks in the Territory during the Term,
Hyseq shall not be obligated to continue any of its activities or to incur any
further costs or expenses related to such aspect.

      9.6 INFRINGEMENT OF COLLABORATION PATENT RIGHTS AND PRODUCT TRADEMARKS.

      (a) Amgen Patent Rights and Joint Patent Rights.

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            (i) Amgen may, but shall not be obligated to, elect to enforce Amgen
      Patent Rights and/or Joint Patent Rights and to enforce its rights in
      Amgen Know-How and the Parties' rights in Joint Know-How against any
      actual, alleged or threatened infringement by Third Parties and to defend
      Amgen Patent Rights and/or Joint Patent Rights Amgen Know-How and the
      Parties' rights in Joint Know-How against any challenges in the Territory.
      In the event Amgen shall so elect to enforce Amgen Patent Rights against a
      Third Party infringement which may in any way affect the rights conferred
      pursuant to this Agreement to Hyseq to Develop, manufacture and
      Commercialize Licensed Products and/or to enforce Joint Patent Rights,
      Amgen shall [***].

            (ii) In the event Amgen does not commence an enforcement and/or
      defense action pursuant to this Section 9.6(a) within [***] after Hyseq
      notifies or is notified by Amgen in writing of an infringement of Amgen
      Patent Rights which may in any way affect the rights conferred pursuant to
      this Agreement to Hyseq to Develop, manufacture and Commercialize Licensed
      Products and/or Joint Patent Rights in the Territory (or of the filing of
      a declaratory judgment action), Hyseq shall be entitled to bring and
      prosecute such an action. If Hyseq elects to bring and prosecute such an
      action, then Hyseq shall [***].

      (b) Hyseq Patent Rights.

            (i) Hyseq may, but shall not be obligated to, elect to enforce Hyseq
      Patent Rights and its rights in Hyseq Know-How against any actual, alleged
      or threatened infringement by Third Parties and to defend Hyseq Patent
      Rights and Hyseq Know-How against any challenges in the Territory. In the
      event Hyseq shall so elect, Hyseq shall [***].

            (ii) In the event Hyseq does not commence an enforcement and/or
      defense action pursuant to this Section 9.6(b) within [***] after Amgen
      notifies or is notified by Hyseq in writing of an infringement of Hyseq
      Patent Rights in the Territory (or of the filing of a declaratory judgment
      action), Amgen shall be entitled to bring and prosecute such an action. If
      Amgen elects to bring and prosecute such an action, then Amgen shall
      [***].

      (c) Product Trademarks.

            (i) The Commercial Lead may, but shall not be obligated to, enforce
      the Product Trademarks against any actual, alleged or threatened
      infringement by Third Parties or from any unfair trade practices, trade
      dress imitation, passing off of counterfeit goods or like offenses. In the
      event the Commercial Lead shall so elect, the Commercial Lead shall
      [***].

            (ii) In the event the Commercial Lead does not commence an
      enforcement and/or defense action pursuant to this Section 9.6(c) within
      [***] after the other Party notifies or is notified by the Commercial Lead
      in writing of any actual, alleged or threatened infringement of the
      Product Trademarks in the Territory (or of the filing of a declaratory
      judgment action) or of any unfair trade practices, trade dress imitation,

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      passing off of counterfeit goods or like offenses, the other Party shall
      be entitled to bring and prosecute such an action. If the other Party
      elects to bring and prosecute such an action, then the other Party shall
      [***].

      (d) The Party bringing suit under this Section 9.6 shall [***] for all
external costs, fees and expenses (including attorneys' fees of outside counsel)
incurred by such Party to carry out the activities described in this Section
9.6; and each Party shall [***] in carrying out the activities described in this
Section 9.6. Recoveries in any actions under this Section 9.6 [***].

      9.7 INFRINGEMENT OF THIRD PARTY RIGHTS.

      (a) The Commercial Lead shall have the first right to defend any actual,
alleged or threatened claim or action which names the Commercial Lead and/or
both Parties and which claims the infringement of (i) Third Party Patent Rights
or other intellectual property rights through the making, having made, using,
selling, offering to sell, importing exporting or otherwise transferring
physical possession of or otherwise transferring title in a Collaboration
Product or (ii) any Third Party trade name, service mark, logo or trademark
(other than as set forth in Sections 14.1(d) or 14.2(d)). If necessary, the
other Party will [***] in any such defense.

      (b) The other Party shall have the right to defend any actual, alleged or
threatened claim or action which names the other Party but does not name the
Commercial Lead or, in the event the Commercial Lead elects not to defend, any
action naming both Parties and which claims the infringement of (i) Third Party
Patent Rights or other intellectual property rights through the making, having
made, using, selling, offering to sell, importing exporting or otherwise
transferring physical possession of or otherwise transferring title in a
Collaboration Product or (ii) any Third Party trade name, service mark, logo or
trademark (other than as set forth in Sections 14.1(d) or 14.2(d)). If
necessary, the Commercial Lead will [***] in any such defense.

      (c) A Party defending a suit pursuant to this Section 9.7 [***] for all
external costs and expenses (including attorneys' fees of outside counsel)
incurred in carrying out the activities described in this Section 9.7; and each
Party shall [***] incurred in carrying out the activities described in this
Section 9.7. Pursuant to Section 14.3, Losses in any actions under this Section
9.7 [***].

      9.8 COOPERATION.

      (a) Each Party shall promptly notify the other upon becoming aware of (i)
any actual, alleged or threatened Third Party claim or action against Hyseq
and/or Amgen for infringement of any Third Party trade name, service mark, logo
or trademark through the Development, manufacturing or Commercialization of a
Collaboration Product; or Third Party Patent Rights or other intellectual
property rights through the making, having made, use, selling, offering to sell,
importing, exporting or otherwise transferring physical possession of or
otherwise transferring title in or to Collaboration Products in the Territory;
or (ii) any Third Party infringement of the Amgen Trademarks, Hyseq Trademarks,
Product Trademarks, Collaboration Patent Rights, Amgen Know-How, Hyseq Know-How
or Joint Know-How.

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      (b) The Parties shall confer with each other regarding the bringing or
defense of any suit under Section 9.6 and/or 9.7 including, if necessary [***].
If the Party bringing or defending such suit finds it necessary or desirable to
[***].

      (c) Neither Party shall enter into any settlement of any suit brought or
defended under Section 9.6 and/or 9.7 that affects the other Party's rights or
interests [***].

      (d) A Party bringing or defending suit under Section 9.6 and/or 9.7 shall
notify the other Party of all substantive developments with respect to such
enforcement or defensive actions including, but not limited to, all material
filings, court papers and other related documents, substantive settlement
negotiations and offer of settlement.

      9.9 [***].

      (a) Hyseq, on behalf of itself and its directors, employees, officers,
shareholders, agents, successors and assigns [***]Amgen, its directors,
employees, officers, shareholders, agents, successors and assigns [***].

      (b) Amgen, on behalf of itself and its directors, employees, officers,
shareholders, agents, successors and assigns [***] Hyseq, its directors,
employees, officers, shareholders, agents, successors and assigns [***].

      9.10 TECHNICAL ASSISTANCE. In addition to other assistance explicitly set
forth in this Agreement, during the period of the Term, Amgen and Hyseq shall
each provide the other Party with reasonable technical assistance relating to
the use of such Amgen Know-How and Hyseq Know-How, respectively, and Joint
Know-How solely to the extent permitted under the license(s) granted to the
other Party in this Agreement. In addition, during the Term each Party shall
make its employees, consultants and agents reasonably available upon reasonable
notice during normal business hours at their respective places of employment to
consult with the other Party on issues relating to any aspect of the subject
matter of this Agreement and in connection with any request from any Regulatory
Authority, including those relating to regulatory, scientific and technical
issues.

      9.11 EMPLOYEE OBLIGATIONS. Prior to beginning work relating to any aspect
of the subject matter of this Agreement and/or being given access to Hyseq
Know-How, Amgen Know-How or Joint Know-How or the Confidential Information of
the other Party, each employee, consultant or agent of Hyseq and Amgen shall
have signed or shall be required to sign a non-disclosure and invention
assignment agreement pursuant to which each such person shall agree to comply
with all of the obligations of Hyseq or Amgen, as appropriate, substantially
including: (a) promptly reporting any invention, discovery, process, software
program or other intellectual property right, as appropriate within Hyseq
Know-How, Amgen Know-How or Joint Know-How; (b) assigning to Hyseq or Amgen, as
appropriate, all of his or her right, title and interest in and to any such
invention, discovery, process, software program or other intellectual property
right; (c) cooperating in the preparation, filing, prosecution, maintenance,
enforcement and defense of any Collaboration Patent Rights and the enforcement
and defense of Amgen Know-How, Hyseq Know-How and Joint Know-How; (d) performing
all acts and signing, executing, acknowledging and delivering any and all
papers, documents and instruments required for effecting the

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obligations and purposes of this Agreement and (e) abiding by the obligations of
confidentiality and non-use set forth in this Agreement. It is understood and
agreed that any such non-disclosure and invention assignment agreement need not
be specific to this Agreement.

      9.12 PATENT MARKING. Collaboration Products marketed and sold by the
Commercial Lead hereunder shall be marked with appropriate patent numbers or
indicia of Collaboration Patent Rights, to the extent permitted by law in those
countries of the Territory in which such markings have notice value as against
infringers of patents.

      9.13 THIRD PARTY RESEARCH AGREEMENTS. The Parties shall, through the
Steering Committee, agree upon and coordinate Third Party material transfer
agreements and collaboration agreements with academic or governmental research
institutions related to the Development of Collaboration Products or involving
the use of Collaboration Products, in a manner so as to conserve the available
quantities of the Parties' research materials and to avoid compromise of the
Parties' abilities to fulfill their responsibilities under the Program Plan and
so as to maintain access to relevant intellectual property rights. The form of
any such Third Party material transfer agreement or collaboration agreement
shall be agreed upon by the Parties. Notwithstanding the above, other than with
respect to Collaboration Products, neither Party may transfer the other Party's
Materials to any such academic or governmental research institution, without the
express written consent of the other Party. In the event any invention or
know-how resulting from such material transfer agreement or collaboration
agreement has applicability outside the scope of this Agreement, and both
Parties desire to have access to such invention or know-how for uses outside the
scope of this Agreement, the Parties shall ensure that they each have the
opportunity to separately license the rights to such invention or know-how.

                                   ARTICLE 10
                            PAYMENTS; RECORDS; AUDIT

      10.1 PAYMENTS.

      (a) U.S. Dollars. All payments to be made under this Agreement shall be
made in U.S. Dollars by bank wire transfer in immediately available funds to a
bank account designated from time-to-time by the Party receiving the funds.

      (b) Foreign Exchange. Currencies other than United States Dollars shall be
converted into the United States Dollar equivalent at the average rate of
exchange for the Calendar Quarter to which such payments relate (as reported in
Bloomberg Professional, a service of Bloomberg L.P.) or in the event Bloomberg
Professional is not available then The Wall Street Journal, for the currency of
the country in which the sale is made.

      (c) Late Payments. Any amounts not paid by a Party when due under this
Agreement shall be subject to interest from and including the date payment is
due through and including the date upon which such Party has made a wire
transfer of immediately available funds into an account designated by the other
Party of such payment at a rate equal to the lesser of (i) the sum of [***]plus
the annual prime rate or successive annual prime rates of interest quoted in the
Money Rates section of the on-line edition of the Wall Street Journal (at

                                      30.
<PAGE>

http://www.interactive.wsj.com) calculated daily on the basis of a 365-day year
or (ii) the highest rate permitted by applicable law.

      (d) Blocked Currency. With respect to receipt of a foreign currency for
sales of Collaboration Products, if the Commercial Lead and its Affiliates are
unable to convert such foreign currency into United States Dollars for reasons
beyond their respective control, or are restricted by law or regulation from
remitting funds from any country of sale, the Commercial Lead shall cause such
payment to be made by deposit to the credit and account of both Parties (or
their respective nominee(s)) in any commercial bank designated by the Commercial
Lead in the applicable country. The Commercial Lead shall deliver to the other
Party proper evidence of such deposit.

      (e) Withholding Taxes. Any taxes, assessments and fees to be withheld by
the Commercial Lead under the laws, rules or regulations of any foreign country
for the account of the other Party shall be promptly paid by the Commercial Lead
for and on behalf of the other Party to the appropriate governmental authority,
and the Commercial Lead shall furnish the other Party with an original copy of
the official receipt for the payment of such tax within [***] of payment. Any
such tax, assessment and fee actually paid on the other Party's behalf shall be
deducted from any payments due to the other Party. The Commercial Lead agrees to
make all lawful and reasonable efforts to minimize such taxes, assessments and
fees to the other Party.

      10.2 RECORDS; AUDIT. The Parties shall keep or cause to be kept such
records as are required in sufficient detail to track and determine, in a manner
consistent with GAAP, the accuracy of calculations of all sums or credits due
under this Agreement to accurately account for all items within the Operating
Profit or Loss account. Such records shall be retained for a period of the later
of: (i) a [***] period following the year in which any payments were made
hereunder, and (ii) the expiration of the applicable tax statute of limitations
(or any extensions thereof), or such longer period as may be required by law.
Once per Calendar Year each Party shall have the option to engage, at its own
expense, an independent certified public accountant, appointed by the auditing
Party and reasonably acceptable to the audited Party, to examine in confidence
the books and records of the Party being audited as may be necessary to
determine, with respect to any Calendar Year, the correctness or completeness of
any report or payment required to be made under this Agreement; provided
however, that the books and records for any particular Calendar Year shall only
be subject to one audit. The report of such accountant shall be limited to a
certificate verifying any report made or payment submitted by the audited Party
during such period but may include, in the event the accountant shall be unable
to verify the correctness of any such payment, information relating to why such
payment is unverifiable. All information contained in any such certificate shall
be deemed the Confidential Information of the audited Party hereunder. If any
audit performed under this Section 10.2 (showing the calculation of a
reimbursement or payment amount) discloses a variance of more than [***] from
the amount of the original report, the audited Party shall bear the full cost of
the performance of such audit. Upon the expiration of [***] following the end of
any particular Calendar Year, the calculation of any such amounts payable with
respect to such particular Calendar Year shall be binding and conclusive upon a
Party entitled to such audit and the other Party or its Affiliates shall be
released from any liability or accountability with respect to such amounts for
such Calendar Year.

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                                   ARTICLE 11
                                  PUBLICATIONS

      11.1 PROCEDURE. The Steering Committee shall determine the overall
strategy for publication and presentation of results of pre-clinical and
clinical studies of Collaboration Products. [***]. Each Party to this Agreement
recognizes that the publication of papers regarding results of and other
information regarding the activities under this Agreement, including oral
presentations and abstracts, may be beneficial to both Parties provided such
publications are subject to reasonable controls to protect Confidential
Information. In particular, it is the intent of the Parties to maintain the
confidentiality of any Confidential Information included in any patent
application until such patent application has been published. Accordingly, each
Party will have the right to review and approve any paper proposed for
publication by the other Party, including oral presentations and abstracts,
which utilizes data generated under this Agreement and/or includes Confidential
Information of the other Party. Before any such paper is submitted for
publication or an oral presentation is made, the Party publishing or presenting
will deliver a complete copy of the paper or materials and abstracts for oral
presentation to the other Party at least [***] prior to submitting the paper to
a publisher or making the presentation. The other Party will review any such
paper and give its comments to the publishing Party within [***] after the
delivery of such paper to the other Party. With respect to oral presentation
materials and abstracts, the other Party will make reasonable efforts to
expedite review of such materials and abstracts, and will return such items as
soon as practicable to the presenting Party with appropriate comments, if any,
but in no event later than [***] after the date of delivery to the other Party.
The publishing Party will comply with the other Party's request to delete
references to the other Party's Confidential Information in any such paper,
materials and abstracts and agrees to withhold publication of same for an
additional [***] in order to permit the Parties to obtain patent protection, if
either of the Parties deems it necessary, in accordance with the terms of this
Agreement.

      11.2 CREDIT. Any such publication or presentation will include recognition
of the contributions of the other Party according to standard practice for
assigning scientific credit, either through authorship or acknowledgment, as may
be appropriate.

                                   ARTICLE 12

                                 CONFIDENTIALITY

      12.1 TREATMENT OF CONFIDENTIAL INFORMATION. The Parties agree that during
the Term, and for a period of [***] after this Agreement expires or terminates,
a Party receiving Confidential Information of the other Party shall (a) maintain
in confidence such Confidential Information to the same extent such Party
maintains its own confidential or proprietary information or trade secrets of
similar kind and value (but at a minimum each Party shall use [***] maintain
such Confidential Information in confidence); (b) not disclose such Confidential
Information to any Third Party without the prior written consent of the
disclosing Party, except for disclosures to its Affiliates and, pursuant to
Section 18.7, to authorized subcontractors who agree to be bound by obligations
of non-disclosure and non-use at least as stringent as those contained in this
Article 12; and (c) not use such Confidential Information for any purpose except
those purposes permitted by this Agreement. Neither Party shall knowingly
disclose to

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the other Party any Third Party information or know-how that such Party does not
have the legal right to disclose to the other Party and/or has a contractual
obligation not to disclose to the other Party.

      12.2 AUTHORIZED DISCLOSURE. Notwithstanding any other provision of this
Agreement, a Party may disclose Confidential Information of the other Party:

      (a) to the extent and to the persons and entities as required by an
applicable law, rule, regulation, legal process, court order or the rules of the
National Association of Securities Dealers or of a Regulatory Authority;

      (b) as necessary to file, prosecute or defend those patent applications or
patents for which either Party has the right to assume filing, prosecution,
defense or maintenance, pursuant to Section 9.4 of this Agreement;

      (c) to prosecute or defend litigation or otherwise establish rights or
enforce obligations pursuant to this Agreement, but only to the extent that any
such disclosure is necessary; or

      (d) in the event of a Recall, by the Party responsible for such Recall
pursuant to Section 4.9.

The Party required or intending to disclose the other Party's Confidential
Information under Sections 12.2(a) or (c) shall first have given prompt notice
to such other Party to enable it to seek any available exemptions from or
limitations on such disclosure requirement and shall reasonably cooperate in
such efforts by the other Party.

      12.3 TRANSFER OF MATERIALS. For purposes of this Agreement, the Parties
anticipate that each Party may transfer certain of its Materials to the other
Party. Each Party agrees that it will use such Materials of the other Party only
in accordance with the terms and conditions of this Agreement and will not
transfer such Materials to any Third Party without the consent of the other
Party, except as expressly permitted under this Agreement.

      12.4 PUBLICITY; TERMS OF AGREEMENT. The Parties agree that the existence
of and the material terms of this Agreement shall be considered Confidential
Information of both Parties, subject to the special authorized disclosure
provisions set forth below in this Section 12.4 (in lieu of the authorized
disclosure provisions set forth in Section 12.2, to the extent of any conflict)
and without limiting the generality of the definition of Confidential
Information. The Parties will mutually agree on the text of a press release
announcing the execution of this Agreement. Thereafter, if either Party desires
to make a public announcement concerning this Agreement or the terms hereof,
such Party shall give reasonable prior advance notice of the proposed text of
such announcement to the other Party for its prior review and approval, such
approval not to be unreasonably withheld or delayed. A Party shall not be
required to seek the permission of the other Party to repeat any information as
to the terms of this Agreement that has already been publicly disclosed by such
Party in accordance with the foregoing or by the other Party. Either Party may
disclose the terms of this Agreement to potential investors who agree to be
bound by obligations of non-disclosure and non-use at least as stringent as
those contained in this Article

                                      33.
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12. The Parties acknowledge that Amgen and/or Hyseq may be obligated to file a
copy of this Agreement with the U.S. Securities and Exchange Commission with its
next quarterly report on Form 10-Q, an annual report on Form 10-K or a current
report on Form 8-K or with any registration statement filed with the U.S.
Securities and Exchange Commission pursuant to the Securities Act of 1933, as
amended, and each such Party shall be entitled to make such filing, provided
however, that it requests confidential treatment of the more sensitive terms
hereof to the extent such confidential treatment is reasonably available to the
filing Party under the circumstances then prevailing. In the event of any such
filing, the filing Party will provide the non-filing Party with an advance copy
of the Agreement marked to show provisions for which the filing Party intends to
seek confidential treatment, and the filing Party shall reasonably consider the
non-filing Party's timely comments thereon.

                                   ARTICLE 13
                    REPRESENTATIONS, WARRANTIES AND COVENANTS

      13.1 MUTUAL REPRESENTATIONS AND WARRANTIES. Each Party hereby represents
and warrants to the other Party that as of the Effective Date:

      (a) Power and Authority. It has the corporate power, authority and legal
right to enter into this Agreement and perform its obligations hereunder and has
taken all necessary corporate action on its part required to authorize the
execution and delivery of the Agreement and the performance of its obligations
hereunder, including without limitation the right to grant the licenses
hereunder.

      (b) Binding Agreement. This Agreement has been duly executed and delivered
on behalf of Hyseq and constitutes a legal, valid and binding obligation of
Hyseq that is enforceable against it in accordance with its terms.

      (c) No Conflict. The execution, delivery and performance of this Agreement
does not conflict with, and would not result in a breach of any agreement,
instrument or understanding, oral or written, to which it is a party or by which
it may be bound, nor violate any material law or regulation of any court,
governmental body or administrative or other agency having jurisdiction over it.

      (d) Validity. It is aware of no action, suit, inquiry or investigation
instituted by any Third Party which questions or threatens the validity of this
Agreement.

      (e) Business [***]. It is not in violation of its charter, bylaws, or any
other organizational document, or in violation of any law, administrative
regulation, ordinance or order of any court or governmental agency, arbitration
panel or authority applicable to it [***]. Except as may be set forth in any
documents filed with the Securities and Exchange Commission, as required to be
filed by it under the Securities Act or Exchange Act, as the case may be, [***].

      13.2 MUTUAL COVENANTS. Each Party hereby covenants to the other Party as
follows:

      (a) No Misappropriation. It shall not knowingly misappropriate the trade
secret of a Third Party in its activities to Develop, manufacture or
Commercialize Collaboration Products.

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      (b) No Debarment. In the course of the Development, manufacture and
Commercialization of Collaboration Products and during the Term, such Party
shall not knowingly use and shall not have knowingly used any employee or
consultant who is or has been debarred by a Regulatory Authority or, to the best
of such Party's knowledge, is or has been the subject of debarment proceedings
by a Regulatory Authority.

      (c) No Conflict. It shall not during the term of this Agreement grant any
right, license, consent or privilege to any Third Party(ies) in the Territory
which would conflict with the rights granted to the other Party under this
Agreement, and shall not take any action that would in any way prevent it from
assuming its obligations or granting the rights granted to the other Party under
this Agreement or that would otherwise materially conflict with or adversely
affect its obligations or its assumption of the rights granted to the other
Party under this Agreement.

      (d) Exclusivity. It shall work exclusively with the other Party with
respect to Collaboration Products. It shall not, directly or indirectly, make,
have made, use, sell, offer to sell, import, export or otherwise transfer
physical possession of or otherwise transfer title in (for purposes of
Developing, manufacturing or Commercializing) a [***] in the Territory, nor
license or otherwise enable a Third Party to take such actions during the Term.
[***]

      (e) Compliance. Each Party shall comply with all applicable statutes,
regulations and guidance of Regulatory Authorities in carrying out its
respective activities regarding the Development, manufacture and
Commercialization of Collaboration Products in the Territory.

      (f) Regulatory Data. It shall store and provide the other Party access to
source data supporting all Regulatory Filings and Regulatory Approvals for the
longer of (i) [***] or (ii) the time period required by any applicable
Regulatory Authority in the Territory. [*] of the first Collaboration Product,
it shall also make its employees, consultants and agents reasonably available
upon reasonable notice from the other Party to consult with the other Party on
issues relating to the Collaboration Product or relating to requests from any
Regulatory Authority in the Territory.

      (g) Formation of Legal Entity. In the event either Party determines that
the formation of a partnership or other legal entity co-owned by the Parties to
further the Development, manufacture and Commercialization of the Collaboration
Products would be beneficial for legal, tax or other reasons, the other Party
covenants that it shall cooperate and take all reasonable steps necessary to
form such entity.

      13.3 ADDITIONAL REPRESENTATIONS, WARRANTIES AND COVENANTS OF HYSEQ.

      (a) Corporate Existence. Hyseq hereby represents and warrants to Amgen
that as of the Effective Date of this Agreement it is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Nevada, and has full corporate power and authority and the legal right to own
and operate its property and assets and to carry on its business as it is now
being conducted and as contemplated in this Agreement.

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      (b) [***]. In entering into this Agreement, Hyseq hereby represents and
warrants to Amgen that as of the Effective Date of this Agreement it has [***].

      (c) [***]. Hyseq covenants that it shall use [***] to carry out its
obligations in accordance with the terms of this Agreement including, as
applicable, the Development, manufacture and Commercialization of Collaboration
Products in the Territory in accordance with the terms of this Agreement.
Without limiting the generality of the foregoing obligation, Hyseq covenants
that:

            (i) Hyseq shall use [***] to administer a Collaboration Product to a
      patient in a government-approved clinical trial within [***] after the
      Effective Date. In the event Hyseq fails to administer a Collaboration
      Product in such time period then, within [***] after the Effective Date,
      Hyseq shall either [***] or Amgen may terminate this Agreement in
      accordance with Section 16.3.

            (ii) Hyseq shall use [***] to administer a Collaboration Product to
      a patient in a government-approved clinical trial within [***] after the
      Effective Date. In the event Hyseq fails to administer a Collaboration
      Product in such time period then, in addition to [***] under subsection
      (i) above and within [***] after the Effective Date, [***] or Amgen may
      terminate this Agreement in accordance with Section 16.3.

            (iii) Hyseq shall use [***] to administer a Collaboration Product to
      a patient in a government-approved clinical trial within [***] after the
      Effective Date. In the event Hyseq fails to administer such Collaboration
      Product in such time period, then Amgen shall have the right to terminate
      this Agreement in accordance with Section 16.3.

      13.4 ADDITIONAL REPRESENTATIONS, WARRANTIES AND COVENANTS OF AMGEN.

      (a) Corporate Existence. Amgen hereby represents and warrants to Hyseq
that as of the Effective Date of this Agreement it is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware, and has full corporate power and authority and the legal right to own
and operate its property and assets and to carry on its business as it is now
being conducted and as contemplated in this Agreement.

      (b) [***]. Amgen covenants that it shall use [***] to carry out its
obligations under the terms of this Agreement including, as applicable, the
Development, manufacture and Commercialization of Collaboration Products.

      13.5 DISCLAIMERS. EXCEPT AS EXPRESSLY PROVIDED HEREIN, THE MATERIALS AND
INFORMATION PROVIDED HEREUNDER ARE BEING PROVIDED "AS IS" AND WITHOUT ANY
REPRESENTATIONS OR WARRANTIES. NEITHER PARTY MAKES ANY REPRESENTATIONS OR
WARRANTIES, EXPRESS OR IMPLIED, OF ANY TYPE WHATSOEVER REGARDING THE MATERIALS
AND INFORMATION. EACH PARTY EXPRESSLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY,
OF FITNESS FOR A PARTICULAR PURPOSE OR OF NONINFRINGEMENT.

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                                   ARTICLE 14
                                 INDEMNIFICATION

      14.1 INDEMNIFICATION BY AMGEN. Amgen hereby agrees to defend, hold
harmless and indemnify (collectively "Indemnify" or "Indemnified") Hyseq and its
Affiliates, agents, directors, officers and employees (the "Hyseq Indemnitees")
from and against any and all Losses resulting directly or indirectly from any
Third Party claims, suits, actions or demands, whether brought during or after
the Term, arising out of (a) any of Amgen's representations and warranties set
forth in this Agreement being untrue in any material respect when made; (b) any
material breach or material default by Amgen of its covenants and obligations
under this Agreement; (c) Amgen's carrying out of activities outside the Program
Plan during the Term or Amgen's [***] of any Third Party engaged by Amgen) in
carrying out its activities set forth in the Program Plan including, without
limitation, manufacturing and Commercialization activities of Amgen; and/or (d)
resulting solely from Hyseq's proper use of Amgen's Trademarks in connection
with a Collaboration Product in accordance with the terms of this Agreement. To
be eligible to be so Indemnified as described in this Section 14.1, the Hyseq
Indemnitees shall provide Amgen with prompt notice of any claims, suits, actions
or demands (with a description of the claim and the nature and amount of any
such Loss) giving rise to the indemnification obligation pursuant to this
Section 14.1 and the exclusive ability to defend such claims, suits, actions or
demands (with the reasonable cooperation of Hyseq Indemnitees); provided
however, that Amgen shall be relieved of its obligations only if any failure by
the Hyseq Indemnitee to deliver prompt notice shall have been prejudicial to its
ability to defend such claims, suits, actions or demands. Hyseq shall have the
right to retain its own counsel, at its own expense, if representation of the
counsel of Amgen would be inappropriate due to actual or potential differing
interests between the Parties. Neither Party shall settle or consent to the
entry of any judgment with respect to any claim for Loss for which
indemnification is sought[***]. Amgen's obligation to Indemnify the Hyseq
Indemnitees pursuant to this Section 14.1 shall not apply to the extent of any
Losses (i) that arise from the [***] of any Hyseq Indemnitee (including but not
limited to that arising from the Development or Commercialization of a
Collaboration Product by Hyseq); (ii) that arise from Hyseq's breach of any
representation, warranty, covenant or obligation under this Agreement; or (iii)
for which Hyseq is obligated to Indemnify the Amgen Indemnitees pursuant to
Section 14.2 of this Agreement.

      14.2 INDEMNIFICATION BY HYSEQ. Hyseq hereby agrees to Indemnify Amgen and
its Affiliates, agents, directors, officers and employees (the "Amgen
Indemnitees") from and against any and all Losses resulting directly or
indirectly from any Third Party claims, suits, actions or demands, whether
brought during or after the Term, arising out of (a) any of Hyseq's
representations and warranties set forth in this Agreement being untrue in any
material respect when made; (b) any material breach or material default by Hyseq
of its covenants and obligations under this Agreement; (c) Hyseq's carrying out
of activities outside the Program Plan during the Term or Hyseq's [***] of any
Third Party engaged by Hyseq) in carrying out its activities set forth in the
Program Plan including, without limitation, Development activities of Hyseq;
and/or (d) resulting solely from Amgen's proper use of Hyseq's Trademarks in
connection with a Collaboration Product in accordance with the terms of this
Agreement. To be eligible to be Indemnified as described above in this Section
14.2, the Amgen Indemnitees shall provide Hyseq with prompt notice of any
claims, suits, actions or demands (with a description of

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the claim and the nature and amount of any such Loss) giving rise to the
indemnification obligation pursuant to this Section 14.2 and the exclusive
ability to defend such claims, suits, actions or demands (with the reasonable
cooperation of Amgen Indemnitees); provided however, that Hyseq shall be
relieved of its obligations only if any failure by the Amgen Indemnitee to
deliver prompt notice shall have been prejudicial to its ability to defend such
claims, suits, actions or demands. Amgen shall have the right to retain its own
counsel, at its own expense, if representation of the counsel of Hyseq would be
inappropriate due to actual or potential differing interests between the
Parties. Neither Party shall settle or consent to the entry of any judgment with
respect to any claim for Loss for which indemnification is sought[***]. Hyseq's
obligation to Indemnify the Amgen Indemnitees pursuant to this Section 14.2
shall not apply to the extent of any Losses (i) that arise from the [***] of any
Amgen Indemnitee (including but not limited to that arising from the manufacture
or Commercialization of Collaboration Product by Amgen); (ii) that arise from
Amgen's breach of any representation, warranty, covenant or obligation under
this Agreement; or (iii) for which Amgen is obligated to Indemnify the Hyseq
Indemnitees pursuant to Section 14.1 of this Agreement.

      14.3 JOINT LIABILITY. Other than as set forth in Section 14.1 or 14.2 and
after exhausting the minimum insurance coverage as listed in the table in
Section 14.4, any and all Losses arising from Third Party claims, suits, actions
or demands, whether brought during or after the Term, resulting directly or
indirectly out of the making, having made, using, selling, having sold, offering
for sale or resale, and/or otherwise Developing, manufacturing, or
Commercializing Collaboration Products (including a claim that a Collaboration
Product caused death or personal injury of any kind) during the Term [***] at
the time such claim is finally determined, whether by judgment, award, decree or
settlement. For avoidance of doubt, prior to Hyseq [***]. In the event a Party
becomes aware of a claim which, if resulting in a Loss, it intends to [***],
such Party shall inform the other Party of such claim [***] after it receives
notice thereof. Subject to Section 9.7, Hyseq shall have the right to assume
direction and control of the defense of any claim alleging a date of injury (or
in the event of a continuing injury alleging the then-most recent date of
injury) to be prior to the Transition Date of the first Collaboration Product,
and Amgen shall have the right to assume direction and control of the defense of
any claim alleging a date of injury (or in the event of a continuing injury
alleging the then-most recent date of injury) to be upon or after the Transition
Date of the first Collaboration Product. The Party not in control of such
defense shall [***] in the defense of the claim and if the Party in control of
such defense finds it necessary or desirable to {***]; provided however, that
the other Party shall have the right to retain its own counsel, at its own
expense, if representation by the counsel of the Party in control would be
inappropriate due to actual or potential differing interests between the Parties
{***]. Neither Party shall settle or consent to the entry of any judgment with
respect to any claim for losses associated with such claim, [***].

      14.4 INSURANCE. Within [***] after the Effective Date, each Party shall at
its own expense procure and maintain during the Term and for a period of [***]
thereafter an insurance policy/policies, including product liability insurance
(but excluding clinical trial insurance policies which shall be required only
while trials are ongoing), adequate to cover its obligations hereunder and which
is/are consistent with normal business practices of prudent companies similarly
situated. Amgen may self-insure and Hyseq may self-insure all or part of any
such obligation consistent with pharmaceutical industry practices but Hyseq
shall at all times maintain the following minimum Third Party insurance
coverage:

<TABLE>
<CAPTION>
                 TYPE OF COVERAGE                               AMOUNT
                 ----------------                               ------
<S>                                                             <C>
       Commercial General Liability Insurance                    [***]
</TABLE>

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       Product Liability Insurance                               [***]

       Excess Liability Insurance                                [***]

       Clinical Trial Liability Insurance                        [***]

       Workman's Compensation                                    [***]

      Each insurance policy required by and procured by a Party under this
Section 14.4 shall name the other Party as an additional insured. Such insurance
shall not be construed to create a limit of the insuring Party's liability with
respect to its indemnification obligations under this Article 14. Each Party
shall provide the other Party with a certificate of insurance or other evidence
of such insurance and/or self-insurance, upon request. Each Party shall provide
the other Party with written notice at least [***] prior to the cancellation,
non-renewal or a material change in such insurance or self-insurance which
materially adversely affects the rights of the other Party hereunder.

      14.5 PRE-EFFECTIVE DATE LOSSES. In connection with this Agreement, Hyseq
shall not assume or be liable for any Losses resulting from or arising in
connection with the use by Amgen (or any Third Party under Amgen's direction) of
any Collaboration Product on or prior to the Effective Date.

      14.6 LIMITATION OF LIABILITY. NEITHER PARTY NOR ITS RESPECTIVE AFFILIATES
SHALL BE LIABLE FOR SPECIAL, EXEMPLARY, CONSEQUENTIAL OR PUNITIVE DAMAGES,
WHETHER IN CONTRACT, WARRANTY, TORT, STRICT LIABILITY OR OTHERWISE INCURRED BY
THE OTHER PARTY IN CONNECTION WITH THIS AGREEMENT, INCLUDING BUT NOT LIMITED TO
DAMAGES MEASURING LOST PROFITS OR BUSINESS OPPORTUNITIES.

                                   ARTICLE 15
                              COLLABORATION OPT OUT

      15.1 AMGEN'S OPT-OUT RIGHT. Subject to this Article 15, Amgen shall have
the right to elect to opt out of this Agreement and to grant Hyseq an exclusive
license (even as to Amgen) under the terms and conditions as set forth in that
certain License Agreement attached hereto as Schedule IV, at which time this
Agreement shall be terminated in accordance with Section 16.8.

      15.2 EXERCISE. Amgen may exercise the opt-out right described in Section
15.1 by providing Hyseq with written notice thereof at any time between [***].
Notwithstanding the foregoing, if Hyseq, after the foregoing [***], Amgen's
opt-out right under this Article 15 [***] as provided in this Section 15.2.

      15.3 LICENSE AGREEMENT. In the event Amgen shall have exercised its right
pursuant to Section 15.1, Hyseq and Amgen shall execute the License Agreement
attached hereto as Schedule IV not less than [***] following Amgen's written
notification provided under Section 15.2.

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                                   ARTICLE 16
                              TERM AND TERMINATION

      16.1 TERM. This Agreement shall become effective on the Effective Date and
shall remain in full force and effect, unless earlier terminated pursuant to
this Article 16, for such time as the Collaboration Products are being Developed
or Commercialized by the Parties.

      16.2 TERMINATION FOR CONVENIENCE. Hyseq may terminate this Agreement at
any time by providing [***] prior written notice of termination to Amgen. The
effects of such termination will occur in accordance with Section [***].

      16.3 TERMINATION BY AMGEN. In the event Hyseq shall not [***] pursuant to
either Section 13.3(c)(i) or 13.3(c)(ii) or shall not timely administer a
Collaboration Product to a patient pursuant to Section 13.3(c)(iii), Amgen shall
have the right, in its sole discretion, to terminate this Agreement by providing
[***] prior written notification of termination to Hyseq. The effects of such
termination will occur in accordance with Section [***].

      16.4 TERMINATION FOR MATERIALLY ADVERSE CLINICAL DEVELOPMENT. If [***]the
results of any clinical trial or of any decision by a Regulatory Authority
regarding a Collaboration Product constitutes a materially adverse change in the
commercial prospects or prospects for approval of any Collaboration Product,
then Amgen may terminate this Agreement by providing [***] prior written
notification of termination to Hyseq. The effects of such termination will occur
in accordance with Section [***].

      16.5 MUTUAL CONSENT. This Agreement shall terminate upon the mutual
written consent of the Parties and, unless otherwise specified in such written
consent, shall be effective [***] after the date of last signature of the
Parties to such mutual written consent. The effects of such termination will
occur in accordance with Section [***].

      16.6 TERMINATION FOR DEFAULT.

      (a) In the event any material representation or warranty made hereunder or
under the Warrant Purchase Agreement by either Party shall have been untrue in
any material respect ("Representation Default"), or upon any material breach or
material default of a material obligation of this Agreement or the Warrant
Purchase Agreement by a Party ("Performance Default"), the Party not in default
("Non-Defaulting Party") must first give the other Party ("Defaulting Party")
written notice thereof ("Notice of Default"), which notice must state the nature
of the Representation Default or Performance Default in reasonable detail and
must request the Defaulting Party cure such Representation Default or
Performance Default within [***]. During any such [***] period after receipt or
delivery of a Notice of Default under this Section 16.6(a) for which termination
of this Agreement, in whole or in part, is a remedy, all of the Party's
respective rights and obligations under the affected parts of this Agreement,
including but not limited to Development, manufacture and Commercialization,
shall (to the extent applicable) remain in force and effect. If the Defaulting
Party shall dispute the existence, extent or nature of any default set forth in
a Notice of Default, the Parties shall use good faith efforts to resolve the
dispute.

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      (b) Hyseq Default. In the event of a Representation Default or a
Performance Default by Hyseq that shall not have been cured within the period
set forth in Section 16.6(a) above after receipt of a Notice of Default, Amgen,
at its option, may terminate this Agreement upon [***] prior written notice,
unless such Representation Default is an unintentional Representation Default of
the Warranty Agreement and Amgen did not provide Notice of Default within [***]
after the Effective Date. The effects of such termination will occur in
accordance with Section [***]. In addition, in the event of termination pursuant
to such uncured Representation Default as provided in the foregoing sentence,
Amgen will be entitled to receive a refund of all money paid.

      (c) Amgen Default. In the event of a Representation Default or a
Performance Default by Amgen that shall not have been cured within the period
set forth in Section 16.6(a) after receipt of a Notice of Default, Hyseq, at its
option, may terminate this Agreement upon [***] prior written notice. The
effects of such termination will occur in accordance with Section [***]. In
addition, in the event of termination pursuant to such uncured Representation
Default as provided in the foregoing sentence, Hyseq will be entitled to receive
a refund of all money paid.

      16.7 BANKRUPTCY.

      (a) [***] may terminate the Agreement if [***] shall file in any court or
agency pursuant to any statute or regulation of any state or country, a petition
in bankruptcy or insolvency or for reorganization or for an arrangement or for
the appointment of a receiver or trustee of [***] or of its assets, or if [***]
proposes a written agreement of composition or extension of its debts, or if
[***] shall be served with an involuntary petition in bankruptcy or seeking
reorganization, liquidation, dissolution, winding-up arrangement, composition or
readjustment of its debts or any other relief under any bankruptcy, insolvency,
reorganization or other similar act or law of any jurisdiction now or hereafter
in effect, or there shall have been issued a warrant of attachment, execution,
distraint or similar process against it, filed in any insolvency proceeding, and
such petition shall not be dismissed within ninety (90) days after the filing
thereof, or if [***] shall propose or be a party to any dissolution or
liquidation, or if [***] shall make an assignment for the benefit of creditors.
The effects of such termination will occur in accordance with Section [***].

      (b) All rights and licenses granted under or pursuant to this Agreement by
Amgen or Hyseq are, and shall otherwise be deemed to be, for purposes of Section
365(n) of the U.S. Bankruptcy Code, licenses of rights to "intellectual
property" as defined under Section 101 of the U.S. Bankruptcy Code. The Parties
agree that each Party shall retain and may fully exercise all of its rights and
elections under the U.S. Bankruptcy Code. The Parties further agree that, in the
event of the commencement of a bankruptcy proceeding by or against a bankrupt
Party under the U.S. Bankruptcy Code, the other Party shall be entitled to a
complete duplicate of (or complete access to, as appropriate) any intellectual
property and all embodiments of such intellectual property, and same, if not
already in the other Party's possession, shall be promptly delivered to the
other Party (a) upon any such commencement of a bankruptcy proceeding, upon the
other Party's written request therefor, unless the non-bankrupt Party (or a
trustee on behalf of the non-bankrupt Party) elects to continue to perform all
of its obligations under this Agreement or (b) if not delivered under (a) above,
upon the rejection of this Agreement by or on behalf of the non-bankrupt Party,
upon written request therefor by the other Party.

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      16.8 OPT OUT BY AMGEN. In the event Amgen shall provide notice of its
election to opt out of this Agreement pursuant to Section 15.2, this Agreement
shall automatically terminate within [***] after Hyseq's receipt of such opt-out
notice. The effects of such termination will occur in accordance with Section
[***].

      16.9 EFFECTS OF TERMINATION. In addition to any other remedies which may
be available at law or equity, upon termination of this Agreement the rights and
obligations of the Parties shall be as set forth in this Section 16.9.

      (a) Upon termination of this Agreement in accordance with either Sections
[***], the following rights and obligations shall apply:

            (i) The following provisions shall remain in full force and effect
      after the expiration or termination of this Agreement: Article 1, Section
      7.1, Subsection 8.3(f), Section 9.1, Subsection 9.2(b), Subsection 9.2(e)
      (solely to the extent relevant to the license granted to Amgen pursuant to
      Section 9.2(b)), Subsection 9.3(b), Subsection 9.3(c) (solely to the
      extent relevant to the license granted to Amgen pursuant to Section
      9.2(b)), Subsection 9.4(a)(i) (solely to the extent pertaining to Joint
      Patent Rights); Subsection 9.4(a)(ii) (with respect to the claims of Joint
      Patent Rights not relating to Collaboration Products); Subsection 9.4(b),
      Subsection 9.4(d) (first sentence only, with Amgen having the rights of
      the Commercial Lead); Subsection 9.6(a)(i) (with Hyseq being included
      within the definition of a Third Party and Amgen bearing all costs and
      expenses and being entitled to all recoveries from such actions),
      Subsection 9.6(a)(ii) (with respect to the claims of Joint Patent Rights
      not relating to products which may in any way affect the rights conferred
      to Amgen to Develop, manufacture and Commercialize Collaboration Products,
      with Hyseq bearing all costs and expenses and being entitled to all
      recoveries from such actions); Subsection 9.6(b)(i) (with respect to the
      claims of Hyseq Patent Rights not relating to products which may in any
      way affect the rights conferred to Amgen to Develop, manufacture and
      Commercialize Collaboration Products and with Hyseq bearing all costs and
      expenses and being entitled to all recoveries from such actions),
      Subsection 9.6(b)(ii) (only with respect to products which may in any way
      affect the rights conferred to Amgen to Develop, manufacture and
      Commercialize Collaboration Products) and with Amgen bearing all costs and
      expenses and being entitled to all recoveries from such actions),
      Subsection 9.6(c)(i) (with Amgen having the rights of the Commercial
      Lead), Section 9.7 (with Amgen having the rights of the Commercial Lead),
      Section 9.8(b)-(d) (except that a Party bringing a suit under Section 9.6
      shall reimburse the other Party for its reasonable costs and expenses for
      assisting therewith), Section 9.9, Section 9.11 (solely with respect to
      any ongoing possession or exchange of the other Party's Confidential
      Information), Section 9.12 (with Amgen having the obligations of the
      Commercial Lead); Article 10 (only with respect to surviving rights and
      obligations pursuant to this Section 16.9(a) and to accrued rights and
      obligations pursuant to Section 16.12), Article 11 (with Amgen having the
      rights of the Commercial Lead), Article 12, Section 13.1, Section 13.2(f),
      Sections 13.3(a)-(b), Section 13.4(a), Section 13.5, Article 14, Section
      16.1, Section 16.9, Section 16.11, Section 16.12, Article 17 and Article
      18.

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            (ii) Amgen shall have sole and full control, authority and
      responsibility for conducting, funding and pursuing all aspects of
      Development, manufacture and Commercialization of Collaboration Products
      in the Field of Use in the Territory, with no obligation of accounting to
      Hyseq.

            (iii) Pursuant to Section 4.5, Hyseq shall promptly transfer to
      Amgen all right, title and interest in (or comparable rights in) all
      Regulatory Filings and Regulatory Approvals then in its name for all
      Collaboration Products and shall notify the appropriate Regulatory
      Authorities and take any other action reasonably necessary to effect such
      transfer of ownership. Hyseq shall assign to Amgen Hyseq's right, title
      and interest in the Product Trademarks. At Amgen's request and expense,
      within [***] after such request Hyseq will provide Amgen with access to
      any pre-clinical and clinical information (reasonably necessary to the
      continued Development and Commercialization of a Collaboration Product),
      and Hyseq will assist Amgen in responding to any request or inquiry by a
      Regulatory Authority regarding such information.

            (iv) Amgen shall have the right to use Hyseq's Trademarks in the
      selling of any existing inventory of Collaboration Product(s) (and to use
      Promotional Materials it then has on hand, provided however, that Amgen
      promptly creates new Promotional Materials which do not use Hyseq's
      corporate name and/or logo), with no obligation of accounting to Hyseq.

            (v) Hyseq shall within [***] (other than with respect to Third Party
      agreements entered into pursuant to Section 6.8, in which case by no later
      than completion of its obligations, if any, under Section 16.9(a)(vii)
      below), at the request of Amgen, assign (if assignable under its terms) to
      Amgen all of Hyseq's rights and obligations under any then-existing Third
      Party agreements limited specifically to Collaboration Products, regarding
      the making, having made, use, selling, offering to sell, and importing,
      exporting or otherwise transferring physical possession of or otherwise
      transferring title in or to Collaboration Products and shall not (until
      receiving notice of whether or not Amgen desires such an assignment)
      terminate or amend any such Third Party agreement. Otherwise, Hyseq shall,
      at the request of Amgen, sublicense (if sublicensable under its terms) to
      Amgen all of Hyseq's rights and obligations under any then-existing Third
      Party agreement regarding the making, having made, use, selling, offering
      to sell, and importing, exporting or otherwise transferring physical
      possession of or otherwise transferring title in or to Collaboration
      Products and shall not (until receiving notice of whether or not Amgen
      desires such a sublicense) terminate or amend any such Third Party
      agreement. Such assignment or sublicense shall be made for no additional
      consideration and be under the same terms and conditions as the underlying
      agreement.

            (vi) Hyseq shall within [***] (other than with respect to Amgen
      Material and Manufacturing Information, in which case by no later than
      completion of its obligations, if any, under Section 16.9(a)(vii) below)
      destroy, or at Amgen's request return, all of Amgen's Confidential
      Information (other than with respect to maintaining one (1) archival copy
      of Confidential Information related thereto for its legal files, for the
      sole

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      purpose of determining its obligations under this Agreement) and
      Materials, and shall provide Amgen with certification by an officer of
      Hyseq that all such Confidential Information and Materials have been
      destroyed or returned to Amgen, as appropriate.

            (vii) In the event Hyseq shall have been the Manufacturing Lead at
      termination and (1) have been using a Third Party contract manufacturer to
      manufacture Collaboration Products, it shall only be obligated, with
      respect to the manufacture and supply of Collaboration Products under this
      Agreement, to assign its agreement with each such Third Party contract
      manufacturer to Amgen or (2) have been manufacturing Collaboration
      Products at its own facilities, it shall remain responsible for supplying
      the amounts of Collaboration Products that it was obligated to supply at
      the time of such termination (consistent with the clinical and/or
      commercial forecasts, as applicable, and other terms and conditions of the
      Process Development/Manufacturing Plan section of the Program Plan) for a
      [***] to allow Amgen to obtain an alternate source of supply, if
      necessary, pursuant to a transition plan which shall be approved by [***]
      of the Steering Committee and which shall set forth the responsibilities
      and schedules for transferring manufacturing responsibilities as
      expeditiously as possible with the goal of providing for an uninterrupted
      supply of Collaboration Product of suitable quality and quantity required
      for the Development and Commercialization to proceed. Hyseq shall have the
      right to charge Amgen and Amgen shall pay Hyseq's Standard Cost plus [***]
      for the supply of Collaboration Products pursuant to this Section
      16.9(a)(vii) and shall also reimburse Hyseq for all Third Party payments
      made to any Third Party pursuant to Section 6.8 (to the extent such
      agreements have not already been transferred pursuant to Section
      16.9(a)(v)). Once manufacturing responsibility has been successfully
      transferred, Hyseq shall no longer be responsible for any obligations
      pursuant to Article 6. In the event Hyseq is obligated to continue to
      supply Collaboration Products under this Section 16.9(a)(vii), Amgen shall
      use [***] to identify one or more viable Third Party manufacturers in
      order to transfer manufacturing operations as soon as commercially
      reasonable.

            (viii) Amgen hereby agrees to Indemnify the Hyseq Indemnitees from
      and against any and all Losses resulting from any Third Party claims,
      suits, actions or demands resulting directly or indirectly from the
      Development, manufacture or Commercialization of Collaboration Products
      (including a claim that a Collaboration Product caused death or personal
      injury of any kind). To be eligible to be Indemnified as described above
      in this Section 16.9(a)(viii), the Hyseq Indemnitees shall provide Amgen
      with prompt notice of any claim (with a description of the claim and the
      nature and amount of any such Loss) giving rise to the indemnification
      obligation pursuant to this Section 16.9(a)(viii) and the exclusive
      ability to defend such claim (with the reasonable cooperation of Hyseq
      Indemnitees); provided however, that Amgen shall be relieved of its
      obligations only if any failure by the Hyseq Indemnitee to deliver prompt
      notice shall have been prejudicial to its ability to defend such action.
      Hyseq shall have the right to retain its own counsel, at its own expense,
      if representation of the counsel of Amgen would be inappropriate due to
      actual or potential differing interests between the Parties. Neither Party
      shall settle or consent to the entry of any judgment with respect to any
      claim for Loss for which indemnification is sought[***]. Amgen's
      obligation to

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      Indemnify the Hyseq Indemnitees pursuant to this Section 16.9(a)(viii)
      shall not apply to the extent of any Losses (i) that arise from the [***]
      of any Hyseq Indemnitee (including but not limited to that arising from
      the Development of Collaboration Product by Hyseq); (ii) that arise from
      Hyseq's breach of any representation, warranty, covenant or obligation
      under this Agreement; or (iii) for which Hyseq is obligated to Indemnify
      the Amgen Indemnitees pursuant to Section 14.2 of this Agreement.

            (ix) Except as expressly set forth in this Section 16.9(a), all
      other rights and obligations shall terminate.

      (b) Upon termination of this Agreement in accordance with Section [***],
the following rights and obligations shall apply:

            (i) The following provisions shall remain in full force and effect
      after the expiration or termination of this Agreement: Article 1, Section
      7.1, Subsection 8.3(f), Section 9.1, Subsection 9.4(a) (solely to the
      extent pertaining to Joint Patent Rights), Subsection 9.4(d) (with the
      Commercial Lead and other Party on the date of termination retaining their
      respective rights thereunder, unless survival of this Subsection would
      have a materially adverse effect on either Party), Subsection 9.6(a)(i),
      Subsection 9.6(a)(ii) (solely to the extent pertaining to Joint Patent
      Rights), Subsection 9.6(b)(i), Subsection 9.6(c) (with the Commercial Lead
      and other Party on the date of termination retaining their respective
      rights thereunder unless survival of this Subsection would have a
      materially adverse effect on either Party), Subsection 9.6(d) (only with
      respect to actions pertaining to Joint Patent Rights under surviving
      Section 9.6 or brought under 9.6(c)), Section 9.7 (with the Commercial
      Lead and other Party on the date of termination retaining their respective
      rights thereunder), Subsections 9.8(b)-(d), Section 9.9, Article 10 (only
      with respect to surviving rights and obligations pursuant to this Section
      16.9(b) and accrued rights and obligations pursuant to Section 16.12),
      Article 11 (with the Commercial Lead and other Party on the date of
      termination retaining their respective rights thereunder), Article 12,
      Section 13.1, Section 13.2(f), Sections 13.3(a)-(b), Section 13.4(a),
      Section 13.5, Article 14, Section 16.1, Section 16.9, Section 16.11,
      Section 16.12, Article 17 and Article 18.

            (ii) Each Party shall within [***] destroy, or at the other Party's
      request return, all of the other Party's Confidential Information (other
      than with respect to maintaining one (1) archival copy of Confidential
      Information related thereto for its legal files, for the sole purpose of
      determining its obligations under this Agreement) and Materials, and shall
      provide the other Party with certification by an officer of such Party
      that all such Confidential Information and Materials have been destroyed
      or returned to the other Party, as appropriate.

            (iii) Except as expressly set forth in this Section 16.9(b), all
      other rights and obligations shall terminate

      (c) Upon termination of this Agreement under Section [***], as a
consequence of an Amgen Default pursuant to Section [***] or under Section
[***], and upon entering into the License Agreement attached in Schedule IV
(which, at the request of Hyseq, shall be timely

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executed by Amgen), in addition to the rights and obligations of the Parties
pursuant to such License Agreement the following rights and obligations shall
apply (provided however if Hyseq elects not to execute such License Agreement,
the rights and obligations of the Parties shall be governed by the terms and
conditions of Section [***]):

            (i) The following provisions shall remain in full force and effect
      after the expiration or termination of this Agreement: Article 1,
      Subsection 8.3(f), Article 10 (only with respect to surviving rights and
      obligations pursuant to this Section 16.9(c) and accrued rights and
      obligations pursuant to Section 16.12), Article 11 (with the Commercial
      Lead and other Party on the date of termination retaining their respective
      rights thereunder), Article 12, Section 13.1, Section 13.2(f), Sections
      13.3(a)-(b), Section 13.4(a) and Section 13.5, Article 14, Section 16.1,
      Section 16.9, Section 16.11, Section 16.12, Article 17 and Article 18.

            (ii) Pursuant to Section 4.5, Amgen shall promptly transfer to Hyseq
      all right, title and interest in (or comparable rights in) all Regulatory
      Filings and Regulatory Approvals then in its name for all Collaboration
      Products, and shall notify the appropriate Regulatory Authorities and take
      any other action reasonably necessary to effect such transfer of
      ownership. Amgen will also deliver to Hyseq all correspondence between
      Amgen and Regulatory Authorities relating to all Regulatory Filings and
      Regulatory Approvals.

            (iii) Hyseq shall have the right to use Amgen's Trademarks in the
      selling of existing inventory of Collaboration Product(s) (and to use
      Promotional Materials it then has on hand, provided however, that Hyseq
      promptly creates new Promotional Materials' which do not use Amgen's
      corporate name and/or logo).

            (iv) Amgen shall within [***] (other than with respect to
      information necessary or useful to complete its obligations under Section
      16.9(c)(vi) below, in which case by no later than completion of its
      obligations, if any, under Section 16.9(c)(vi) below) destroy, or at
      Hyseq's request return, all of Hyseq's Confidential Information (other
      than with respect to maintaining one (1) archival copy of Confidential
      Information related thereto for its legal files, for the sole purpose of
      determining its obligations under this Agreement) and Materials, and shall
      provide Hyseq with certification by an officer of Amgen that all such
      Confidential Information and Materials have been destroyed or returned to
      Hyseq, as appropriate.

            (v) Amgen shall within [***] (other than with respect to Third Party
      agreements entered into pursuant to Section 6.8, in which case by no later
      than completion of its obligations, if any, under Section 16.9(c)(vi)
      below), at the request of Hyseq, assign (if assignable under its terms) to
      Hyseq all of Amgen's rights and obligations under any then-existing Third
      Party licenses having a license grant limited specifically to
      Collaboration Products, regarding the making, having made, use, selling,
      offering to sell, and importing, exporting or otherwise transferring
      physical possession of or otherwise transferring title in or to
      Collaboration Products and shall not (until receiving notice of whether or
      not Hyseq desires such an assignment) terminate or amend any such Third
      Party license. Otherwise, Amgen shall, at the request of Hyseq,

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      sublicense (if sublicensable under its terms) to Hyseq all of Amgen's
      rights and obligations under any then-existing Third Party licenses
      regarding the making, having made, use, selling, offering to sell, and
      importing, exporting or otherwise transferring physical possession of or
      otherwise transferring title in or to Collaboration Products and shall not
      (until receiving notice of whether or not Hyseq desires such a sublicense)
      terminate or amend any such Third Party license. Such assignment or
      sublicense shall be made for no additional consideration and be under the
      same terms and conditions as the underlying agreement.

            (vi) In the event Amgen shall have been the Manufacturing Lead at
      termination and had been manufacturing Collaboration Products at its own
      facilities, it shall remain responsible for supplying the amounts of
      Collaboration Products that it was obligated to supply at the time of such
      termination (consistent with the clinical and/or commercial forecasts, as
      applicable, and other terms and conditions of the Process
      Development/Manufacturing Plan section of the Program Plan) for [***] to
      allow Hyseq itself manufacture or to obtain an alternate source of supply,
      if necessary, pursuant to a transition plan which shall be consistent with
      Section 6.7 and approved by [***] of the Steering Committee and which
      shall set forth the responsibilities and schedules for transferring
      manufacturing responsibilities as expeditiously as possible with the goal
      of providing for an uninterrupted supply of Collaboration Product of
      suitable quality and quantity required for the Development and
      Commercialization to proceed. Amgen shall have the right to charge Hyseq
      and Hyseq shall pay Amgen's Standard Cost [***] for the supply of
      Collaboration Products pursuant to this Section 16.9(c)(vi) and shall also
      reimburse Amgen for all Third Party payments made to any Third Party
      pursuant to Section 6.8 (to the extent such agreements have not already
      been transferred pursuant to Section 16.9(c)(v)). Once manufacturing
      responsibility has been successfully transferred, Amgen shall no longer be
      responsible for any obligations pursuant to Article 6. In the event Amgen
      is obligated to continue to supply Collaboration Products under this
      Section 16.9(c)(vi), Hyseq shall [***] to identify one or more viable
      Third Party manufacturers to which it may transfer manufacturing
      operations as soon as commercially reasonable.

            (vii) Except as expressly set forth in this Section 16.9(c), all
      other rights and obligations shall terminate.

      16.10 ACQUISITION. In the event that, during the term of this Agreement, a
Third Party shall acquire, directly or indirectly, [***] of the shares of a
Party's stock entitled to vote for the election of directors of such Party (the
"Acquired Party"), the other Party shall have the right, within [***] of such
acquisition, to assume the rights and responsibilities of, and shall be deemed,
the Development Lead, Regulatory Lead, Manufacturing Lead and Commercial Lead
(with the Acquired Party being designated as the "Co-Detailer") and the Acquired
Party shall take all actions to facilitate such transition to the other Party,
including without limitation, those as set forth hereinbelow; provided however,
that all other rights and obligations of the Parties shall remain in full force
and effect:

      (a) The Acquired Party shall transfer to the other Party ownership of all
Regulatory Filings and Regulatory Approvals then in its name for all
Collaboration Products and shall notify the appropriate Regulatory Authorities
and take any other action reasonably necessary to effect

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such transfer of ownership. The Acquired Party shall assign to the other Party
all of the Acquired Party's right, title and interest in the Product Trademarks.

      (b) The Acquired Party shall, at the request of the other Party, assign
(if assignable under its terms) to the other Party all of the Acquired Party's
rights and obligations under any then-existing Third Party licenses having a
license grant limited specifically to Collaboration Products, regarding the
making, having made, use, selling, offering to sell, and importing, exporting or
otherwise transferring physical possession of or otherwise transferring title in
or to Collaboration Products and shall not (until receiving notice of whether or
not the other Party desires such an assignment) terminate or amend any such
Third Party license. Otherwise, the Acquired Party shall, at the request of the
other Party, sublicense (if sublicensable under its terms) to the other Party
all of the Acquired Party's rights and obligations under any then-existing Third
Party licenses regarding the making, having made, use, selling, offering to
sell, and importing, exporting or otherwise transferring physical possession of
or otherwise transferring title in or to Collaboration Products and shall not
(until receiving notice of whether or not the other Party desires such a
sublicense) terminate or amend any such Third Party license.

      (c) In the event the Acquired Party shall have been the Manufacturing Lead
on the date of acquisition and (1) have been using a Third Party contract
manufacturer to manufacture Collaboration Products, it shall only be obligated,
with respect to the manufacture and supply of Collaboration Products under this
Agreement, to assign its agreement with each such Third Party contract
manufacturer to the other Party or (2) have been manufacturing Collaboration
Products at its own facilities, it shall remain responsible for supplying the
amounts of Collaboration Products that it was obligated to supply at the time of
such termination (consistent with the clinical and/or commercial forecasts, as
applicable, and other terms and conditions of the Process
Development/Manufacturing Plan section of the Program Plan) for [***] to allow
the other Party to obtain an alternate source of supply, if necessary, pursuant
to a transition plan which shall be approved by [***] of the Steering Committee
and which sets forth responsibilities and schedules for transferring
manufacturing responsibilities as expeditiously as possible with the goal of
providing for an uninterrupted supply of Collaboration Product of suitable
quality and quantity required for the Development and Commercialization to
proceed. Once manufacturing responsibility has been successfully transferred,
the Acquired Party shall no longer be responsible for the manufacture and supply
of Collaboration Products to the other Party for the Development and
Commercialization of Collaboration Products in the Territory and making any
decision with respect thereto and shall no longer be responsible for any process
development work to support quality assurance, improving manufacturing/cost
efficiency and commercial scale-up manufacturing. In the event the Acquired
Party is obligated to continue to supply Collaboration Products under this
Section 16.10(c), the other Party shall [***] to identify one or more viable
Third Party manufacturers in order to transfer manufacturing operations as soon
as commercially reasonable.

      16.11 TRANSITION. After a notice of termination has been delivered
pursuant to any one of Sections 16.2 to 16.8, each Party shall, in no event in
excess of [***] after the delivery date of such notice (other than with respect
to obligations which explicitly exceed such [***] period), assist (and, other
than Wind Down Costs, be responsible for its own costs and expenses) in the
transition of affairs as set forth in this Article 16 in a timely, reasonable
and businesslike manner. Such assistance shall include, but not be limited to
(i) making its personnel and other resources

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reasonably available to the other Party, as necessary and (ii) transferring
copies of all relevant information, files or data containing Information and all
Materials to the non-terminating Party. Thereafter, unless explicitly set forth
in Sections 16.2 through 16.9, as appropriate, the Parties shall have no further
obligation to assist in such transition.

      16.12 ACCRUED RIGHTS. Termination, relinquishment or expiration of any
licenses under this Agreement or of this Agreement for any reason in accordance
with this Article 16 shall be without prejudice to any rights which shall have
accrued to the benefit of either Party or any liability incurred by either Party
prior to the effective date of such termination, relinquishment or expiration
and shall not preclude either Party from pursuing all rights and remedies it may
have hereunder or at law or in equity with respect to any breach of this
Agreement nor prejudice either Party's right to obtain performance of any
obligation.

                                   ARTICLE 17
                               DISPUTE RESOLUTION

      17.1 DISPUTES. The Parties recognize that disputes as to certain matters
may from time to time arise during the term of this Agreement which relate to
either Party's rights and/or obligations hereunder and which are not resolved by
the Steering Committee (e.g. disputes pursuant to Section 2.4(b)(v)). It is the
objective of the Parties to establish procedures to facilitate the resolution of
disputes arising from, concerning or in any way relating to this Agreement in an
expedient manner by mutual cooperation and without resort to litigation. To
accomplish this objective, the Parties agree to follow the procedures set forth
in this Section 17.1 if and when such a dispute arises under this Agreement
(other than with respect to disputes to be resolved in accordance with Section
2.4(b)(i)-(iv) or, as set forth in this Agreement, disputes explicitly excluded
from being resolved pursuant to this Article 17). The Parties shall undertake
good faith efforts to resolve any such dispute in good faith. [***] after such
notice is received. [***].

            [***]: [***]

            [***]: [***]

[***] Notwithstanding the above, either Party shall be entitled at all times and
without delay to seek equitable relief.

      17.2 GOVERNING LAW; JUDICIAL RESOLUTION. Resolution of all disputes
arising out of or related to this Agreement or the performance, enforcement,
breach or termination of this Agreement and any remedies relating thereto, shall
be governed by and construed under the substantive laws of the State of
California, as applied to agreements executed and performed entirely in the
State of California by residents of the State of California, without regard to
conflicts of law rules. Any dispute arising under this Agreement shall be
submitted to a state or federal court of competent jurisdiction in California;
provided however, that if Amgen is the initiating Party in a dispute, its shall
bring such suit in a state or federal court which has jurisdiction over
Sunnyvale, California; and if Hyseq is the initiating Party in a dispute, its
shall bring such suit in a state or federal court which has jurisdiction over
Thousand Oaks, California.

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      17.3 PATENT AND TRADEMARK DISPUTE RESOLUTION. Notwithstanding the above
Section 17.2, as between the Parties, any dispute, controversy or claim relating
to the scope, validity, enforceability or infringement of any Collaboration
Patent Rights or of any Amgen Trademark, Hyseq Trademark or Product Trademark
shall be submitted to a court of competent jurisdiction in the Territory in
which such patent or trademark rights were granted or arose. Notwithstanding the
foregoing, any dispute, controversy or claim relating to the scope, validity,
enforceability or infringement of any United States patent application or patent
within Collaboration Patent Rights shall be submitted to a court of competent
jurisdiction in the State of California.

                                   ARTICLE 18
                                     GENERAL

      18.1 CONDITIONS TO CLOSING. The obligations of each Party to the other
Party under this Agreement are subject to fulfillment, on or before the
Effective Date, of the execution and delivery of the Warrant Purchase Agreement.

      18.2 FORCE MAJEURE. Both Parties shall be excused from the performance of
their obligations under this Agreement to the extent that such performance is
prevented by Force Majeure and the nonperforming Party promptly provides notice
of the prevention to the other Party. Such excuse shall be continued so long as
the condition constituting Force Majeure continues and the nonperforming Party
uses reasonable efforts to remove the condition. When such circumstances arise,
the Parties shall discuss what, if any, modification of the terms of this
Agreement may be required in order to arrive at an equitable solution.

      18.3 NOTICES. Any notice required or permitted to be given under this
Agreement shall be in writing, shall specifically refer to this Agreement and
shall be deemed to have been sufficiently given for all purposes if mailed by
first class certified or registered mail, postage prepaid, express delivery
service or personally delivered, or if sent by facsimile, electronic
transmission confirmed. Unless otherwise notified in writing, the mailing
addresses and fax numbers for notice of the Parties shall be as described below.

            For Hyseq:   Hyseq Pharmaceuticals, Inc.
                         670 Almanor Ave.
                         Sunnyvale, CA 94085-1710
                         Facsimile: (408) 524-8415
                         Attn: General Counsel

                         With a copy to: Chief Financial Officer

                                      50.
<PAGE>

            For Amgen:   Amgen Inc.
                         One Amgen Center Drive
                         Thousand Oaks, CA 91320-1799
                         Fax: (805) 499-6058
                         Attention:  Vice President, Licensing

                         With a copy to: Corporate Secretary

      18.4 MAINTENANCE OF RECORDS. Each Party shall keep and maintain all
records required by law or regulation with respect to Collaboration Products and
shall make copies of such records available to the other Party upon request.

      18.5 NO STRICT CONSTRUCTION. This Agreement has been prepared jointly and
shall not be strictly construed against either Party.

      18.6 PERFORMANCE BY AFFILIATES. Each of Amgen and Hyseq acknowledge that
obligations under this Agreement may be performed by Affiliates of Amgen and
Hyseq and that each of Amgen and Hyseq may grant its respective Affiliates a
license or sublicense to (or covenant not to sue under) Amgen Technology, Hyseq
Technology, Joint Know-How, Joint Patent Rights, Amgen Trademarks, Hyseq
Trademarks and Product Trademarks, as applicable, only to the extent and only
for so long as such license or sublicense or covenant not to sue is necessary
for such Affiliate to perform such tasks. Each of Amgen and Hyseq guarantee
performance of this Agreement by its Affiliates, notwithstanding any assignment
to Affiliates in accordance with Section 18.8 below. Wherever in this Agreement
the Parties delegate responsibility to Affiliates or local operating entities,
the Parties agree that such entities may neither make decisions inconsistent
with this Agreement, amend the terms of this Agreement nor act contrary to its
terms in any way. The Party granting a license or sublicense to its Affiliates
shall forward to the other Party a copy of each fully executed license or
sublicense agreement, within [***] of the execution of each such license or
sublicense agreement.

      18.7 SUBCONTRACTING. The Parties acknowledge and agree that the following
portions of the work involved in Development, manufacture and Commercialization
of Collaboration Products may be subcontracted to a Third Party by the
responsible Party, and the Party entering into such subcontract may as part of
such subcontract grant to such Third Party a license or sublicense to Amgen
Technology, Hyseq Technology, Joint Know-How, Joint Patent Rights, Amgen
Trademarks, Hyseq Trademarks and Product Trademarks, as applicable, only to the
extent and only for so long as such license or sublicense is necessary for such
Third Party to perform such tasks; provided however, that the responsible Party
remains responsible for the satisfactory accomplishment of such work in
accordance with the terms and conditions of this Agreement and that the
subcontractor shall enter into a written agreement binding such subcontractor to
the obligations the responsible Party has to the other Party (and containing any
other provisions normal and customary for similar types of agreements): (i) the
Development Lead may contract with/establish clinical sites, investigators and
CROs pursuant to Section 3.2; (ii) the Parties may subcontract to a Third Party
manufacturer pursuant to Section 6.7; and (iii) the Commercialization Lead may,
in its sole discretion, decide to unilaterally enter into agreements with
distributors or sublicensees for commercial distribution of Collaboration
Products; (provided however, that any proceeds from a sublicense activity shall
be credited to the

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Operating Profit or Loss account). The subcontracting Party shall use [***] to
enter into an Agreement with the bidder that is best able to meet the Parties'
mutual requirements, taking into consideration such factors as price, quality,
capacity, quantity, reliability and reputation. The subcontracting Party shall
forward to the other Party a copy of each fully executed subcontracting
agreement, within [***] of the execution of each such agreement.

      18.8 ASSIGNMENT. Except as set forth in Sections 18.6 and 18.7, [***].
This Agreement shall be binding on the successors and assigns of the assigning
Party, and the name of a Party appearing herein shall be deemed to include the
name(s) of such Party's successors and permitted assigns to the extent necessary
to carry out the intent of this Agreement. Any assignment or attempted
assignment by either Party in violation of the terms of this Section 18.8 shall
be null and void and of no legal effect. The assigning Party shall forward to
the other Party a copy of those portions of each fully executed assignment
agreement which relate to the assumption of the rights and responsibilities of
the assigning Party, within [***] of the execution of such assignment agreement.

      18.9 COUNTERPARTS. This Agreement may be executed in two (2) or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

      18.10 SEVERABILITY. If any one or more of the provisions of this Agreement
are held to be invalid or unenforceable by any court of competent jurisdiction
from which no appeal can be or is taken, the provision shall be considered
severed from this Agreement and shall not serve to invalidate any remaining
provisions hereof. The Parties shall make a good faith effort to replace any
invalid or unenforceable provision with a valid and enforceable one such that
the objectives contemplated by the Parties when entering this Agreement, as
evidenced by the terms of this Agreement in accordance with Section 18.19, may
be realized.

      18.11 HEADINGS. The headings for each Article and Section in this
Agreement have been inserted for convenience of reference only and are not
intended to limit or expand on the meaning of the language contained in the
particular Article or Section. Unless otherwise specified, (a) references in
this Agreement to any Article, Section, Exhibit or Schedule shall mean
references to such Article, Section, Exhibit or Schedule of this Agreement, (b)
references in any Section to any clause are references to such clause of such
Section, and (c) references to any agreement, instrument or other document in
this Agreement refer to such agreement, instrument or other document as
originally executed or, if subsequently varied, replaced or supplemented from
time-to-time, as so varied, replaced or supplemented and in effect at the
relevant time of reference thereto.

      18.12 FURTHER ACTIONS. Each Party agrees to execute, acknowledge and
deliver such further instruments and to do all such other acts as may be
necessary or appropriate in order to carry out the purposes and intent of the
Agreement.

      18.13 INDEPENDENT CONTRACTORS. The relationship between Hyseq and Amgen
created by this Agreement is solely that of independent contractors. This
Agreement does not create any agency, distributorship, employee-employer,
partnership, joint venture or similar business relationship between the Parties.
Neither Party is a legal representative of the other Party, and

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neither Party can assume or create any obligation, representation, warranty or
guarantee, express or implied, on behalf of the other Party for any purpose
whatsoever. Each Party shall use its own discretion and shall have complete and
authoritative control over its employees and the details of performing its
obligations under this Agreement.

      18.14 NO BENEFIT OF THIRD PARTIES. The representations, warranties,
covenants and agreements set forth in this Agreement are for the sole benefit of
the Parties hereto and their successors and permitted assigns, and they shall
not be construed as conferring any rights on any Third Parties.

      18.15 USE OF NAMES, LOGOS OR SYMBOLS. Subject to Sections 5.5, 12.2(a) and
12.4, no Party hereto shall use, and no rights are granted in or to, the names
or trademarks (including the names "Amgen" and "Hyseq"), physical likeness,
employee names or owner symbol of any other Party for any purpose (including,
without limitation, private or public securities placements) without the prior
written consent of the affected Party, such consent not to be unreasonably
withheld or delayed so long as such use of name is limited to objective
statement of fact rather than for endorsement purposes. Neither Party shall use
any trademark which either substantially resembles or is confusingly similar to,
misleading or deceptive with respect to, or which dilutes any of the other
Party's trademarks in connection with the subject matter of this Agreement.

      18.16 NO WAIVER. Any delay in enforcing a Party's rights under this
Agreement or any waiver as to a particular default or other matter shall not
constitute a waiver of such Party's rights to the future enforcement of its
rights under this Agreement, except with respect to an express written and
signed waiver relating to a particular matter for a particular period of time.

      18.17 OFFSET. Either Party shall be entitled to offset, against any
payments due and payable to the other Party hereunder, all such amounts due and
payable hereunder but not yet paid by the other Party to the Party seeking such
offset. Prior to applying an offset under this Section 18.17, the Party seeking
such offset shall first give the other Party written notice of such due and
payable amounts and shall request the other Party to pay all such due and
payable amounts within [***] from the date of such notice.

      18.18 EXPORT REQUIREMENTS. It is understood and acknowledged that the
transfer of certain commodities and technical data is subject to United States
laws and regulations controlling the export of such commodities and technical
data, including all Export Administration Regulations of the United States
Department of Commerce. Each Party hereby agrees and by entering into this
Agreement gives written assurance that it shall comply with all United States
laws and regulations controlling the export of commodities and technical data
within Information and Materials, that it will be solely responsible for any
violation of any such laws and regulations by itself, its Affiliates or its
sublicensees, and that it will Indemnify, defend and hold the other Party
harmless from any liability in the event of any legal action of any nature
occasioned by such violation, pursuant to Section 14.1 (in the case of Amgen) or
Section 14.2 (in the case of Hyseq).

      18.19 ENTIRE AGREEMENT; AMENDMENT. This Agreement (including all Exhibits
and Schedules, including the Warrant Purchase Agreement) set forth the complete,
final and exclusive agreement and all the covenants, promises, agreements,
warranties, representations,

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conditions and understandings between the Parties hereto and supersedes and
terminates all prior agreements and understandings between the Parties; on the
Effective Date of this Agreement, the Confidential Disclosure Agreement dated
October 10, 2001 (Amgen Reference No. 20018121) is hereby superseded, provided
that all Confidential Information disclosed therein shall be treated as if
disclosed under, and shall be subject to the terms of, this Agreement. There are
no covenants, promises, agreements, warranties, representations, conditions or
understandings, either oral or written, between the Parties other than as are
set forth herein and therein. This Agreement may only be modified or
supplemented in a writing expressly stated for such purpose and signed by an
authorized officer of each Party (i.e., it may not be modified by any purchase
order, change order, acknowledgment, order acceptance, standard terms of sale,
invoice or the like); except that the Steering Committee may amend or update the
Program Plan as expressly permitted hereby.

      18.20 EXHIBITS AND SCHEDULES. All Exhibits and Schedules referenced herein
and attached hereto are incorporated in this Agreement by reference. In case of
any discrepancies between the language incorporated from the Exhibits and
Schedules and the terms of the Sections, the terms of the Sections shall
prevail; provided however, where Sections of the Agreement make explicit
reference to a substantive matter contained in an Exhibit or Schedule, or with
respect to definitions set forth in the Exhibits or Schedules, the substantive
matter or definitions contained in such Exhibit and Schedules shall prevail.

                                      54.
<PAGE>

      IN WITNESS WHEREOF, the Parties have executed this Agreement in duplicate
originals by their duly authorized representatives as of the Effective Date.

AMGEN INC.                              HYSEQ, INC.

                                        (D.B.A. HYSEQ PHARMACEUTICALS)

By:                                     By:
   ------------------------------           ------------------------------

Print Name:                             Print Name:
           ----------------------                   ----------------------

Title:                                  Title:
      ---------------------------              ---------------------------

                                      55.
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                                    EXHIBIT A

                                  DEFINED TERMS

      A.1 "AFFILIATE" shall mean, except as provided below, an individual, a
partnership, a joint venture, a corporation, a trust, an estate, an
unincorporated organization, a government or any department or agency thereof,
or any other entity or any combination of the aforementioned entities that,
directly or indirectly through one or more intermediaries, controls, is
controlled by or is under common control with Amgen or Hyseq. For purposes of
this definition, "control" shall mean the possession, direct or indirect, of the
power to cause the direction of the management and policies of a Party, whether
through ownership of more than fifty percent (50%) of the voting securities of
such Party, by contract or otherwise.

      A.2 "ALFIMEPRASE" shall mean the polypeptide having the amino acid
sequence which is set forth in Exhibit B.

      A.3 "AMGEN KNOW-HOW" shall mean all Information and Material Controlled by
Amgen on or following the Effective Date necessary to Develop, manufacture or
Commercialize Collaboration Products, including but not limited to the following
information: [***].

      A.4 "AMGEN MATERIAL AND MANUFACTURING INFORMATION" shall mean [***].

      A.5 "AMGEN PATENT RIGHTS" shall mean Amgen's rights in (a) those Patent
Rights Controlled by Amgen on the Effective Date with respect to the
Collaboration Products and listed in Exhibit D and (b) all Patent Rights
Controlled by Amgen prior to or during the Agreement that claim Amgen Know-How.

      A.6 "AMGEN TECHNOLOGY" shall mean all Amgen Patent Rights and Amgen
Know-How and Amgen's interest in the Joint Patent Rights and Joint Know-How.

      A.7 "AMGEN TRADEMARKS" shall mean, other than Product Trademarks, any and
all corporate names, service marks, logos or trademarks and trademark
applications (whether or not registered) together with all good will associated
therewith, and any renewals, extensions or modifications thereto either filed or
used by Amgen.

      A.8 "CALENDAR QUARTER" shall mean the respective periods of three (3)
consecutive calendar months ending on either March 31, June 30, September 30, or
December 31 for so long as this License Agreement is in effect.

      A.9 "CALENDAR YEAR" means each successive period of twelve (12) months
commencing on January 1 and ending on December 31.

      A.10 "CMC" shall mean the Chemistry Manufacturing Control section of a
Regulatory Filing.

      A.11 "COLLABORATION PATENT RIGHTS" shall mean Amgen Patent Rights, Hyseq
Patent Rights and Joint Patent Rights.

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-1
<PAGE>

      A.12 "COLLABORATION PRODUCT(s)" shall mean [***]

      A.13 "COMMERCIAL EXPENDITURES" shall have the meaning set forth in
Schedule I.

      A.14 "COMMERCIAL PLAN" shall mean the comprehensive plan and overall
strategy, and any updates thereto, for the Commercialization of Collaboration
Products (in accordance with customary standards for a product of comparable
market potential) including, without limitation, regulatory activities after the
Transition Date, Promotion, Detailing and other pre-launch and post-launch
marketing and sales activities. The Commercial Plan shall include, but not be
limited to, a reasonably detailed description of the schedule of work
activities, responsibility for the work activities and an associated budget.

      A.15 "COMMERCIALIZE" OR "COMMERCIALIZATION" shall mean all activities
after the Transition Date, or prior to the Transition Date upon the approval of
both Parties, (including the preparation and filing of Drug Approval
Applications) of a Collaboration Product relating to the Promotion, Detailing,
and other pre-launch and post-launch marketing and sale activities and shall
include, without limitation, Post-Approval Clinical Studies and regulatory
affairs related to the foregoing.

      A.16 "[***] EFFORTS" shall mean [***].

      A.17 "COMPETITIVE PRODUCT" shall mean [***].

      A.18 "CONFIDENTIAL INFORMATION" shall mean all Information received by
either Party from the other Party pursuant to this Agreement, other than that
portion of such Information which:

            (a)   is publicly disclosed by the disclosing Party, either before
                  or after it becomes known to the receiving Party;

            (b)   was known to the receiving Party, without obligation to keep
                  it confidential, prior to when it was received from the
                  disclosing Party;

            (c)   is subsequently disclosed to the receiving Party by a Third
                  Party lawfully in possession thereof without obligation to
                  keep it confidential;

            (d)   has been publicly disclosed other than by the disclosing Party
                  and without breach of an obligation of confidentiality with
                  respect thereto; or

            (e)   has been independently developed by the receiving Party
                  without the aid, application or use of Confidential
                  Information, as demonstrated by competent written proof.

      A.19 "CONTROL" OR "CONTROLLED" shall mean possession of the ability to
grant a license or sublicense as provided for herein under such intellectual
property right without violating the terms of any agreement or other arrangement
with any Third Party.

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-2
<PAGE>

      A.20 "DETAIL" OR "DETAILING" shall mean, with respect to a Collaboration
Product, an interactive face-to-face visit by a Party's sales representative
with a physician, designated by the Commercial Lead as a member of the target
call audience, at his or her office, at hospitals or at other locations
(excluding exhibits, displays and other forms of communication not involving
face-to-face contact by such sales representative), during which indicated uses,
safety, effectiveness, contraindications, side effects, warnings and/or other
relevant characteristics of a Collaboration Product as approved by a Regulatory
Authority are described in a fair and balanced manner consistent with the FD&C
Act (or equivalent laws in the Territory), as applicable, including, but not
limited to, the regulations at 21 CFR Part 202 and using, as necessary or
desirable, the Product Labeling (as defined herein) or the Promotional Materials
(as defined herein), in an effort to increase physician prescribing preferences
of such Collaboration Product for its approved indicated uses.

      A.21 "DEVELOPMENT" OR "DEVELOP" shall mean all research, pre-clinical and
clinical activities undertaken for a Collaboration Product required to
successfully complete Pivotal Trials in an indication in the Territory. For the
avoidance of doubt, these activities shall include clinical drug development
activities, including among other things: test method development and stability
testing, toxicology, formulation, statistical analysis and report writing,
product approval and registration, and regulatory affairs related to the
foregoing. When used as a verb, "Develop" means to engage in Development.

      A.22 "DEVELOPMENT PLAN" shall mean the comprehensive plan, overall
strategy and timelines, and any updates thereto, for the Development of
Collaboration Products (in accordance with customary standards for a product of
comparable market potential) including, without limitation, the research,
preclinical research, clinical studies, development/manufacturing, clinical and
regulatory activities required to obtain Regulatory Approval(s) in the
Territory. The Development Plan shall include, but not be limited to, a
reasonably detailed description of the schedule of work activities,
responsibility for the work activities and an associated budget.

      A.23 "DOLLAR" shall mean a United States dollar, and "$" shall be
interpreted accordingly.

      A.24 "DRUG APPROVAL APPLICATION" shall mean an application for Regulatory
Approval required before commercial sale or use of a Collaboration Product as a
drug or to treat a particular indication in a regulatory jurisdiction, including
without limitation: (a) (i) a Biologics License Application (BLA) pursuant to 21
C.F.R. 601.2, submitted to the FDA or any successor application or procedure and
(ii) any counterpart of a U.S. BLA in another country in the Territory; and (b)
all supplements and amendments, including supplemental Biologics License
Applications (and any foreign counterparts) that may be filed (e.g., to expand
the label) with respect to the foregoing.

      A.25 "FDA" shall mean the United States Food and Drug Administration, or
any successor thereto.

      A.26 "FIELD OF USE" shall mean [***].

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-3
<PAGE>

      A.27 "FIRST COMMERCIAL SALE" shall mean the initial transfer by a Party of
a Collaboration Product to a Third Party in exchange for cash or some equivalent
to which value can be assigned for the purpose of determining Net Sales,
following Regulatory Approval to market such Collaboration Product.

      A.28 "FORCE MAJEURE" shall mean any occurrence beyond the reasonable
control of a Party that prevents or substantially interferes with the
performance by the Party of any of its obligations hereunder, if such occurs by
reason of any act of God, flood, fire, explosion, earthquake, breakdown of
plant, shortage of critical equipment, loss or unavailability of manufacturing
facilities or material, strike, lockout, labor dispute, casualty or accident, or
war, revolution, civil commotion, acts of public enemies, blockage or embargo,
or any injunction, law, order, proclamation, regulation, ordinance, demand or
requirement of any government or of any subdivision, authority or representative
of any such government, inability to procure or use materials, labor, equipment,
transportation or energy sufficient to meet manufacturing needs without the
necessity of allocation, or any other cause whatsoever, whether similar or
dissimilar to those above enumerated, beyond the reasonable control of such
Party, if and only if the Party affected shall have used reasonable efforts to
avoid such occurrence and to remedy it promptly if it shall have occurred.

      A.29 "GAAP" shall mean United States generally accepted accounting
principles.

      A.30 "HYSEQ KNOW-HOW" shall mean all Information and Materials Controlled
by Hyseq on or following the Effective Date necessary to Develop, manufacture or
Commercialize Collaboration Products and any replication or any part of such
Information or Materials.

      A.31 "HYSEQ PATENT RIGHTS" shall mean Hyseq's rights in all Patent Rights
that claim Hyseq Know-How and that are Controlled by Hyseq on the Effective Date
or during the Agreement.

      A.32 "HYSEQ TECHNOLOGY" shall mean all Hyseq Patent Rights and Hyseq
Know-How and Hyseq's interest in the Joint Patent Rights and Joint Know-How.

      A.33 "HYSEQ TRADEMARKS" shall mean, other than Product Trademarks, any and
all corporate names, service marks, logos or trademarks and trademark
applications (whether or not registered) together with all good will associated
therewith, and any renewals, extensions or modifications thereto either filed or
used by Hyseq.

      A.34 "IND" shall mean an Investigational New Drug application.

      A.35 "INFORMATION" shall mean all tangible and intangible techniques,
technology, practices, trade secrets, inventions (whether patentable or not),
methods, knowledge, know-how, conclusions, skill, experience, test data and
results (including pharmacological, toxicological and clinical test data and
results), analytical and quality control data, results or descriptions, software
and algorithms.

                                      A-4
<PAGE>

      A.36 "JOINT KNOW-HOW" shall mean Information and Materials characterized,
conceived, developed, derived, generated or identified jointly by employees of
or consultants to Hyseq and employees of or consultants to Amgen from the
Effective Date through the Term.

      A.37 "JOINT PATENT RIGHTS" shall mean all Patent Rights that claim or
disclose Joint Know-How.

      A.38 "LOSSES" shall liabilities, costs, fees, expenses and/or losses,
including without limitation reasonable legal costs, expenses and attorneys'
fees for outside counsel.

      A.39 "MAJOR MARKET COUNTRY" shall mean the United States[***].

      A.40 "MATERIALS" shall mean certain biological materials including, but
not limited to, Collaboration Products, screens, animal models, cell lines,
cells, nucleic acids, receptors and reagents.

      A.41 "NET SALES" shall mean all revenues recognized in accordance with
GAAP [***]

      A.42 "OPERATING PROFIT OR LOSS" shall mean, for any period, the total Net
Sales of Collaboration Products less the sum of Collaboration Expenditures.

      A.43 "PATENT RIGHTS" shall mean (i) a pending application for a patent,
including without limitation any provisional, converted provisional, continued
prosecution application, continuation, divisional or continuation-in-part
thereof; or (ii) an issued, unexpired patent (with the term "patent" being
deemed to encompass, without limitation, an inventor's certificate) which has
not been held invalid or unenforceable by a court of competent jurisdiction from
which no appeal can be taken or has been taken within the required time period,
including without limitation any substitution, extension, registration,
confirmation, reissue, re-examination, renewal or any like filing thereof.

      A.44 "PHASE II CLINICAL TRIAL(s)" shall mean those clinical trials on
sufficient numbers of patients that are designed to establish the safety and
preliminary efficacy of a drug for its intended use, and to define warnings,
precautions and adverse reactions that are associated with the drug in the
dosage range to be prescribed and that satisfy the requirements of 21 CFR
312.21(b) (or its successor regulation), or an equivalent foreign clinical
trial.

      A.45 "PHASE IV CLINICAL TRIAL(s)" shall mean those clinical trials,
including safety surveillance studies, conducted under an IND which are agreed
upon by the Commercial Lead and a Regulatory Authority as a condition of
approval or maintenance of approval of a Drug Approval Application for a
Collaboration Product, as the case may be, other than patient registries of
other than a passive, non-interventional nature.

      A.46 "PIVOTAL TRIAL(s)" shall mean those clinical trials on sufficient
numbers of patients that, if the defined end-points are met, are designed (and
agreed to by the FDA, or other Regulatory Authorities in the Territory) based
upon existing data in the same patient population as of the start of the trial
to definitively establish that a drug is safe and efficacious for its intended
use, and to define warnings, precautions and adverse reactions that are
associated with

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-5
<PAGE>

the drug in the dosage range to be prescribed, and which provide pivotal data
supporting Regulatory Approval of such drug or label expansion of such drug and
that satisfy the requirements of 21 CFR 321.21(c), or its successor regulation,
or an equivalent foreign clinical trial.

      A.47 "POST-APPROVAL CLINICAL STUDIES" shall mean those clinical studies,
after Regulatory Approval of a Collaboration Product, approved by the Steering
Committee including, but not limited to, Phase IV Clinical Trials,
pharmacoeconomic studies, pharmacoepidemiology studies, and investigator
sponsored clinical studies and, to the extent requested or modified from time to
time, safety surveillance studies.

      A.48 "PROCESS DEVELOPMENT/MANUFACTURING PLAN" shall mean the comprehensive
plan and overall strategy, and any updates thereto, for process
development/manufacturing scale-up, manufacture, formulation, filling and/or
shipping of selected Collaboration Products (in accordance with customary
standards for a product of comparable market potential). The Process
Development/Manufacturing Plan shall include, but not be limited to, (i) a
reasonably detailed description of the schedule of work activities,
responsibility for the work activities and an associated budget of Collaboration
Products prior to completion of any Pivotal Trial therewith and (ii) a
reasonably detailed description of the schedule of work activities,
responsibility for the work activities and an associated budget of Collaboration
Products upon or after completion of any Pivotal Trial therewith.

      A.49 "PRODUCT LABELING" shall mean (a) the Regulatory Authority-approved
full prescribing information of a Collaboration Product, including any required
patient information and (b) all labels and other written, printed or graphic
matter upon any container, wrapper or any package insert or outsert utilized
with or for a Collaboration Product.

      A.50 "PRODUCT TRADEMARK" shall mean any trademarks and trade names (and
trademark applications (whether or not registered) together with all goodwill
associated therewith, and any renewals, extensions or modifications thereto in
the Territory), trade dress and packaging which (a) are owned by or Controlled
by either Party and (b) are applied to or used with Collaboration Products or
any Promotional Materials.

      A.51 "PROGRAM PLAN" shall mean the comprehensive plan and overall
strategy, and any updates thereto, for the Development, manufacture and
Commercialization of Collaboration Products. The Program Plan shall be comprised
of the Development Plan, Process Development/Manufacturing Plan, Regulatory
Plan, Commercial Plan and other allowable activities (and Other Allowable
Expenditures) and an associated budget for the foregoing.

      A.52 "PROMOTE" OR "PROMOTION" OR "PROMOTING" OR "PROMOTIONAL" shall mean,
with respect to a Collaboration Product, those activities and obligations other
than Detailing undertaken by a Party to encourage sales of such Collaboration
Product including, but not limited to, journal advertising, direct mail
programs, direct-to-consumer advertising, education, convention exhibits, and
other forms of advertising, promotion and any other communication specified in
any Commercial Plan.

                                      A-6
<PAGE>

      A.53 "PROMOTIONAL MATERIALS" shall mean all sales representative training
materials and all written, printed, graphic, electronic, audio or video matter
including, but not limited to, journal advertisements, sales visual aids, direct
mail, direct-to-consumer advertising, Internet postings, broadcast
advertisements, and sales reminder aids (e.g., scratch pads, pens and other such
items) intended for use or used by a Party in connection with any Promotion (as
defined herein) or Detailing of a Collaboration Product, except Product
Labeling.

      A.54 "RECALL" OR "RECALLING" shall mean an event, incident or circumstance
which may result in the need for a "recall" or "market withdrawal" (as such
terms are defined in U.S. regulations in 21 CFR 7.3 or other similar national,
state or local law or regulations) or field alert or field correction of a
Collaboration Product or any lots thereof.

      A.55 "REGULATORY APPROVAL" shall mean any approvals (including
supplements, amendments, pre- and post-approvals and price approvals), licenses,
registrations or authorizations (including designations of a Collaboration
Product as an "Orphan Product" under the Orphan Drug Act), howsoever called, of
any Regulatory Authority, which are necessary for the distribution, importation,
exportation, manufacture, production, use, storage, transport or clinical
testing and/or sale of a Collaboration Product in a regulatory jurisdiction.
Regulatory Approval shall not include any site license for an Amgen
manufacturing facility.

      A.56 "REGULATORY AUTHORITY" shall mean the FDA or any counterpart of the
FDA outside the United States, or other national, supra-national, regional,
state or local regulatory agency, department, bureau, commission, council or
other governmental entity with authority over the distribution, importation,
exportation, manufacture, production, use, storage, transport or clinical
testing and/or sale of a Collaboration Product.

      A.57 "REGULATORY FILINGS" shall mean, collectively, INDs, BLAs,
establishment license applications (ELAs) and drug master files (DMFs),
applications for designation of a Collaboration Product as an "Orphan
Product(s)" under the Orphan Drug Act or any other similar filings (including
any foreign equivalents and further including any related correspondence and
discussions), and all data contained therein, as may be required by the FDA or
equivalent foreign Regulatory Authorities for the Development, manufacture or
Commercialization of a Collaboration Product.

      A.58 "REGULATORY PLAN" shall mean the comprehensive plan or plans and
overall strategy, and any updates thereto, for preparing and filing any and all
Regulatory Filings regarding Collaboration Products (in accordance with
customary standards for a product of comparable market potential) and for
communications with Regulatory Authorities, including all interactions with
respect to such Regulatory Filings. The Regulatory Plan shall include, but not
be limited to, a reasonably detailed description of the schedule of the work
activities, responsibility for the work activities and an associated budget.

      A.59 "TERRITORY" shall mean [***].

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-7
<PAGE>

      A.60 "THIRD PARTY" shall mean any individual, partnership, joint venture,
corporation, trust, estate, unincorporated organization, government or any
department or agency thereof, or any other entity other than Amgen or Hyseq or
an Affiliate of either of them.

      A.61 "TRANSITION DATE" shall mean [***].

      A.62 Each of the following definitions are found in the body of this
Agreement as indicated below:

<TABLE>
<CAPTION>
                     DEFINED TERM                                     LOCATION
                     ------------                                     --------
<S>                                                               <C>
           "ACCME"                                                  Section 5.6
           "ACQUIRED PARTY"                                        Section 16.10
           "AMA"                                                    Section 5.6
           "AMGEN"                                                     Page 1
           "AMGEN INDEMNITEES"                                      Section 14.2
           "CO-DETAILER"                                            Section 5.1
           "COLLABORATION EXPENDITURES"                              Schedule I
           "COMMERCIAL LEAD"                                        Section 5.1
           "DEFAULTING PARTY"                                     Section 16.6(a)
           "DEVELOPMENT EXPENDITURES"                                Schedule I
           "DEVELOPMENT LEAD"                                      Section 3.2(a)
           "EFFECTIVE DATE"                                            Page 1
           "FTE"                                                     Schedule I
           "FTE COSTS"                                               Schedule I
           "GENERAL AND ADMINISTRATIVE EXPENDITURES"                 Schedule I
           "HYSEQ"                                                     Page 1
           "HYSEQ INDEMNITEES"                                      Section 14.1
           "INDEMNIFY" OR "INDEMNIFIED"                             Section 14.1
           "INTERNAL FTE"                                            Schedule I
           "MANUFACTURING LEAD"                                     Section 6.1
           "NON-DEFAULTING PARTY"                                 Section 16.6(a)
           "NOTICE OF DEFAULT"                                    Section 16.6(a)
           "OTHER ALLOWABLE EXPENDITURES"                            Schedule I
           "PARTY" OR "PARTIES"                                        Page 1
           "PERFORMANCE DEFAULT"                                  Section 16.6(a)
           "PhRMA"                                                  Section 5.6
           "PROCESS DEVELOPMENT/MANUFACTURING                        Schedule I
                                EXPENDITURES"
           "REGULATORY EXPENDITURES"                                 Schedule I
           "REGULATORY LEAD"                                        Section 4.1
</TABLE>

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-8
<PAGE>

<TABLE>
<CAPTION>
                     DEFINED TERM                                     LOCATION
                     ------------                                     --------
<S>                                                               <C>
           "REPRESENTATION DEFAULT"                               Section 16.6(a)
           "RCT"                                                    Section 6.7
           "SOPs"                                                  Section 4.9(a)
           "STEERING COMMITTEE"                                     Section 2.2
           "TERM"                                                   Section 16.1
           "WARRANT PURCHASE AGREEMENT"                             Section 7.1
           "WIND DOWN COSTS"                                         Schedule I
</TABLE>

                                      A-9
<PAGE>

                                    EXHIBIT B

                         PROTEIN SEQUENCE OF ALFIMEPRASE

RN   259074-76-5  ZREGISTRY
CN   3-203-Fibrolase [3-serine] (Agkistrodon contortrix contortrix recombinant)
     (9CI)  (CA INDEX NAME)
FS   PROTEIN SEQUENCE
SQL  201
NTE

<TABLE>
<CAPTION>
----------------------------------------------------------------------
 type            ------ location ------         description
----------------------------------------------------------------------
<S>              <C>                       <C>
bridge           Cys-116     - Cys-196     disulfide bridge
bridge           Cys-156     - Cys-180     disulfide bridge
bridge           Cys-158     - Cys-163     disulfide bridge
----------------------------------------------------------------------
</TABLE>

SEQ      1 SFPQRYVQLV IVADHRMNTK YNGDSDKIRQ WVHQIVNTIN EIYRPLNIQF
        51 TLVGLEIWSN QDLITVTSVS HDTLASFGNW RETDLLRRQR HDNAQLLTAI
       101 DFDGDTVGLA YVGGMCQLKH STGVIQDHSA INLLVALTMA HELGHNLGMN
       151 HDGNQCHCGA NSCVMAAMLS DQPSKLFSDC SKKDYQTFLT VNNPQCILNK
       201 P

SEQ3     1 Ser-Phe-Pro-Gln-Arg-Tyr-Val-Gln-Leu-Val-
        11 Ile-Val-Ala-Asp-His-Arg-Met-Asn-Thr-Lys-
        21 Tyr-Asn-Gly-Asp-Ser-Asp-Lys-Ile-Arg-Gln-
        31 Trp-Val-His-Gln-Ile-Val-Asn-Thr-Ile-Asn-
        41 Glu-Ile-Tyr-Arg-Pro-Leu-Asn-Ile-Gln-Phe-
        51 Thr-Leu-Val-Gly-Leu-Glu-Ile-Trp-Ser-Asn-
        61 Gln-Asp-Leu-Ile-Thr-Val-Thr-Ser-Val-Ser-
        71 His-Asp-Thr-Leu-Ala-Ser-Phe-Gly-Asn-Trp-
        81 Arg-Glu-Thr-Asp-Leu-Leu-Arg-Arg-Gln-Arg-
        91 His-Asp-Asn-Ala-Gln-Leu-Leu-Thr-Ala-Ile-
       101 Asp-Phe-Asp-Gly-Asp-Thr-Val-Gly-Leu-Ala-
       111 Tyr-Val-Gly-Gly-Met-Cys-Gln-Leu-Lys-His-
       121 Ser-Thr-Gly-Val-Ile-Gln-Asp-His-Ser-Ala-
       131 Ile-Asn-Leu-Leu-Val-Ala-Leu-Thr-Met-Ala-
       141 His-Glu-Leu-Gly-His-Asn-Leu-Gly-Met-Asn-
       151 His-Asp-Gly-Asn-Gln-Cys-His-Cys-Gly-Ala-
       161 Asn-Ser-Cys-Val-Met-Ala-Ala-Met-Leu-Ser-
       171 Asp-Gln-Pro-Ser-Lys-Leu-Phe-Ser-Asp-Cys-
       181 Ser-Lys-Lys-Asp-Tyr-Gln-Thr-Phe-Leu-Thr-
       191 Val-Asn-Asn-Pro-Gln-Cys-Ile-Leu-Asn-Lys-
       201 Pro

                                       B-1
<PAGE>

                                    EXHIBIT C

                       AMGEN IND AS OF THE EFFECTIVE DATE

                                FDA FILE # [***]

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
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                                       C-1
<PAGE>

                                    EXHIBIT D

                  AMGEN PATENT RIGHTS AS OF THE EFFECTIVE DATE

                                      [***]

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
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                                       D-1
<PAGE>

                                   SCHEDULE I

                      ALLOWABLE COLLABORATION EXPENDITURES
                    TO THE OPERATING PROFIT AND LOSS ACCOUNT

The Parties have agreed to pursue a collaboration with respect to Collaboration
      Products and jointly share certain costs and expenditures related to these
      activities. This Schedule I outlines the understanding of the Parties as
      to which activities and associated expenditures can be submitted for
      consideration in a Program Plan and budget (See Collaboration Program Plan
      Budget, Schedule II) for Development, manufacturing and Commercialization
      of Collaboration Products; [***].

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

<PAGE>

                                   SCHEDULE II

                                      [***]

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      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
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<PAGE>

                                  SCHEDULE III

                           WARRANT PURCHASE AGREEMENT

                                 BY AND BETWEEN

                                   AMGEN INC.

                                       AND

                   HYSEQ, INC. (D.B.A. HYSEQ PHARMACEUTICALS)

<PAGE>

                                   SCHEDULE IV

                                LICENSE AGREEMENT
                            BY AND BETWEEN AMGEN INC.

                                       AND

                   HYSEQ, INC. (D.B.A. HYSEQ PHARMACEUTICALS)

<PAGE>

                                LICENSE AGREEMENT

                                 BY AND BETWEEN

                                   AMGEN INC.

                                       AND

                                   HYSEQ, INC.

                         (D.B.A. HYSEQ PHARMACEUTICALS)

<PAGE>

                                LICENSE AGREEMENT

      THIS LICENSE AGREEMENT (the "License Agreement") is made effective as of
_______________, ______ (the "Effective Date") by and between AMGEN INC., a
Delaware corporation having its principal place of business at One Amgen Center
Drive, Thousand Oaks, California 91320-1799 ("Amgen") and HYSEQ, INC., D.B.A.
HYSEQ PHARMACEUTICALS, INC., a Nevada corporation having its principal place of
business at 670 Almanor Avenue, Sunnyvale, California 94085-1710 ("Hyseq").
Amgen and Hyseq are sometimes referred to herein individually as a "Party" and
collectively as the "Parties".

                                    RECITALS

      WHEREAS, Amgen and Hyseq have been collaborating in the joint development
and commercialization of a protein known as Alfimeprase (and other variants of
Alfimeprase) under the terms and conditions of that certain Collaboration
Agreement between the Parties, dated January 8, 2002 ("Collaboration
Agreement");

      WHEREAS, pursuant to Article 15 of the Collaboration Agreement, Amgen has
elected to exercise its right to convert its right to jointly develop and
commercialize Alfimeprase (and other variants of Alfimeprase) into the grant to
Hyseq of an exclusive license under certain Amgen rights to Develop, manufacture
and Commercialize Alfimeprase (and other variants of Alfimeprase);

      WHEREAS, Hyseq wishes to exclusively license such Amgen rights from Amgen
in connection with the Development, manufacture and Commercialization of the
Licensed Product(s) (as hereinafter defined), on the terms and conditions
herein;

      NOW THEREFORE, based on the foregoing premises and the mutual covenants
and obligations set forth below, the Parties agree as follows:

                                    ARTICLE 1
                                   DEFINITIONS

      Capitalized terms used but not otherwise defined herein have the meanings
provided in EXHIBIT A hereto.

                                       1
<PAGE>

                                    ARTICLE 2
                       GRANT OF LICENSES AND OTHER RIGHTS

      2.1 PATENT LICENSES. Amgen hereby grants to Hyseq an exclusive license
(even as to Amgen) under Amgen Technology to make, have made, use, sell, lease,
offer to sell or lease, have sold, import, export or otherwise exploit, transfer
physical possession of and transfer title or interest in and to Licensed
Products in the Territory.

      2.2 TRADEMARK; COPYRIGHT LICENSES.

      (a) Amgen hereby grants to Hyseq an exclusive royalty-free license, with
the right to grant sublicenses (subject to Hyseq's compliance with Section 2.3),
under Amgen's entire right, title and interest in and to the Product Trademarks,
to use and display the Product Trademarks in connection with Licensed Products
in the Territory. For the avoidance of doubt, Hyseq shall have the right to
select for and use and display with Licensed Products such Trademarks as it
desires.

      (b) Amgen hereby grants to Hyseq an exclusive royalty-free license under
Amgen's entire right, title and interest in any copyrights in and to Promotional
Materials, with the right to grant sublicenses subject to Hyseq's compliance
with Section 2.3 of this License Agreement), to reproduce, distribute copies of,
prepare derivative works of and publicly perform and display such Promotional
Materials in connection with Licensed Products in the Territory solely in
compliance with the terms and conditions of this License Agreement.

      (c) Other than with respect to the rights and licenses granted to Joint
Know-How under this License Agreement, each Party shall have the unrestricted,
royalty-free, worldwide right to make, have made, use, sell, lease, offer to
sell or lease, have sold, import, export or otherwise exploit, or transfer
physical possession of or title in, Joint Know-How, without accounting.

      2.3 SUBLICENSING.

      (a) Hyseq will have the sole right to determine whether to sublicense any
of its rights under Section 2.1 or 2.2. Any such sublicense shall require the
Sublicensee to comply with the obligations of Hyseq as contained herein
(specifically including, without limitation, obligations under Section 6.6,
Article 7 and Section 14.15), and including an obligation of the Sublicensee to
account for and report its sales of Licensed Products on the same basis as if
such sales were Net Sales by Hyseq. Any such sublicense shall provide for the
termination of the sublicense, or the conversion to a license directly between
such Sublicensee and Amgen, at the option of Amgen, upon termination of this
License Agreement pursuant to Article 12. Hyseq shall forward to Amgen a copy of
each fully executed sublicense agreement within [***] of the execution of such
agreement.

      (b) Notwithstanding the sublicensing of all or part of Hyseq's rights and
obligations hereunder, Hyseq shall remain responsible for the full and complete
performance of all of Hyseq's obligations and duties under this License
Agreement. For the avoidance of doubt,

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Hyseq shall forward to Amgen and acknowledges that Amgen shall be entitled to
receive Royalties on Net Sales of Licensed Product(s) sold by Sublicensees
hereunder and that Hyseq shall be responsible to Amgen for paying Royalties due
on Net Sales of Product(s) sold by Sublicensees.

      2.4 ASSIGNMENT TO HYSEQ. Pursuant to Section 16.9(c)(ii) of the
Collaboration Agreement, Amgen shall have transferred or is in the process of
transferring to Hyseq all right, title and interest in all Regulatory Filings
and Regulatory Approvals owned in each case by Amgen and shall have delivered or
is in the process of delivering to Hyseq all correspondence between Amgen and
Regulatory Authorities relating to all Regulatory Filings and Regulatory
Approvals. At Hyseq's request and expense, within [***] after such request Amgen
will provide Hyseq with access to any pre-clinical and clinical information
(reasonably necessary to the continued Development, manufacturing and
Commercialization of a Collaboration Product), and Amgen will assist Hyseq in
responding to any request or inquiry regarding such information by a Regulatory
Authority.

      2.5 MANUFACTURING LICENSE TO HYSEQ. Pursuant to Section 4.1, Amgen shall
grant to Hyseq an exclusive license, with a limited right to sublicense (to
Third Party manufacturers pursuant to Section 4.2), to make, have made and use
Amgen Material and Manufacturing Information solely for the purposes set forth
in Section 3.1 below.

      2.6 RETAINED RIGHTS. With respect to the licenses granted under this
Article 2, Amgen expressly reserves for itself and its Affiliates a
non-transferable, non-sublicensable right to make, have made and use (but not to
transfer, sell, have sold, offer to sell or lease, import, export or otherwise
exploit or transfer possession of, title to or interest in) Licensed Products
under Amgen Technology and Amgen Material and Manufacturing Information which
are solely for internal research purposes unrelated to Licensed Products. For
the avoidance of doubt, Amgen shall further retain all rights in Amgen
Technology and the Amgen Material and Manufacturing Information not expressly
licensed hereunder, including the right to make, have made, use, sell, lease,
offer to sell or lease, have sold, import, export or otherwise exploit, transfer
physical possession of and transfer title or interest in and to products, other
than Licensed Products, for any purpose in the Territory.

                                    ARTICLE 3
                        DEVELOPMENT AND COMMERCIALIZATION

      3.1 DEVELOPMENT AND COMMERCIALIZATION. At its discretion Hyseq shall have
sole and full control, authority and responsibility for conducting, funding and
pursuing all aspects of Development and Commercialization of each said Licensed
Product in the Territory.

      3.2 REGULATORY FILINGS AND REGULATORY APPROVALS. With respect to each
Licensed Product, at its discretion Hyseq will prepare, file and own all right,
title and interest in Regulatory Filings and Regulatory Approvals relating to
each said Licensed Product in the Territory.

                                       3
<PAGE>

      3.3 [***] REPORTS. Hyseq will provide Amgen with detailed written [***]
reports concerning their efforts regarding Development and Commercialization
(pursuant to Article 3) and regarding manufacturing (pursuant to Article 4) of
the Licensed Products. At Amgen's request, Hyseq shall promptly discuss such
[***] report and any progress regarding Development, manufacturing and
Commercialization with Amgen.

                                    ARTICLE 4
                             MANUFACTURE AND SUPPLY

      4.1 MANUFACTURING RIGHT. Hyseq shall be responsible for manufacturing and
supplying Licensed Products for Development and Commercialization in the
Territory and for making all decisions with respect thereto in its sole
discretion, including without limitation, decisions relating to process
development work to support quality assurance, improving manufacturing/cost
efficiency and commercial scale-up manufacturing. For the avoidance of doubt,
Hyseq shall have final decision making authority to fulfill its regulatory
responsibilities over all steps of the manufacturing process (including bulk,
finish and fill, labeling and packaging, lot release and management of
subcontractors).

      4.2 TRANSFER OF MANUFACTURING RESPONSIBILITIES. Transfer of manufacturing
responsibilities from Amgen to Hyseq or to a Third Party manufacturer approved
by Amgen pursuant to Section 6.7 of the Collaboration Agreement will take place
according to Section 16.9(c) of the Collaboration Agreement.

                                    ARTICLE 5
                                  CONSIDERATION

      5.1 CLINICAL MILESTONES.

      (a) Within [***] following the first achievement or occurrence with the
first Licensed Product(s) of each of the following milestone events by
performance of Hyseq or an Affiliate or Sublicensee of Hyseq ("Milestone
Event(s)"), Hyseq shall pay to Amgen the corresponding one-time, non-creditable,
non-refundable milestone payments set forth herein ("Milestone Payment(s)"):

<TABLE>
<CAPTION>
              MILESTONE EVENT                        MILESTONE PAYMENT
              ---------------                        -----------------
<S>                                                  <C>
                (i) [***]                                 [***]
               (ii) [***]                                 [***]
              (iii) [***]                                 [***]
</TABLE>

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<TABLE>
<CAPTION>
              MILESTONE EVENT                        MILESTONE PAYMENT
              ---------------                        -----------------
<S>                                                  <C>
               (iv) [***]                                 [***]
                (v) [***]                                 [***]

                    TOTAL                                 [***]
</TABLE>

      (b) For purposes of clarification, [***]. No Milestone Payment shall be
payable more than once, no matter how many times achieved by one or more
Licensed Product(s). Each such Milestone Payment shall be nonrefundable and
noncreditable against Royalties payable pursuant to Section 5.2 and any other
fees, other Milestone Payments or other payments due Amgen with respect to
Licensed Product(s) under this License Agreement.

      (c) In the event [***] shall be the [***] pursued by Hyseq, and the
Milestone Event(s) set forth in Sections 5.1(a)(i) or 5.1(a)(ii) is/are first
achieved with respect to the [***], Hyseq shall pay to Amgen [***] of the
corresponding Milestone Payment for any such achieved Milestone Event, with the
balance of any such corresponding Milestone Payment being due and payable upon
the achievement of such Milestone Event with respect to [***]. In the event that
Hyseq shall not have obtained Regulatory Approval for [***] in the United
States, [***] gross sales in the United States for the [***] are or exceed
[***], (based on data provided by IMS International, or if such data shall not
be available, based on such other data mutually agreed to by Amgen and Hyseq),
then Hyseq shall immediately pay the balance of any partially paid Milestone
Payment under this Section 5.3(c).

      (d) If the Effective Date of this License Agreement is after the date of
achievement of any Milestone Event(s) set forth in Sections 5.1(a)(i) and
5.1(a)(ii), then the corresponding Milestone Payment of such previously achieved
Milestone Event shall be deemed waived and not payable to Amgen.

      (e) If the Effective Date of this License Agreement is after the date of
achievement of any Milestone Event(s) set forth in Sections 5.1(a)(iii), (iv) or
(v), the corresponding Milestone Payment shall be due within [***] after the
Effective Date of this License Agreement. Notwithstanding the above sentence,
the [***] Regulatory Approval Milestone incurred by Hyseq under Section 7.2 of
the Collaboration Agreement as a consequence of the achievement of any such
Milestone Event shall be creditable against any Milestone Payments due for the
achievement of any Milestone Event(s) set forth in Sections 5.1(a)(iii), (iv) or
(v) prior to or during the Term of this License Agreement.

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      5.2 ROYALTIES. Subject to Sections 5.3 and 5.4, below, Hyseq shall pay to
Amgen a Royalty, based on the following Royalty rates, for annual Net Sales of
each Licensed Product (on a Licensed Product-by-Licensed Product basis) by
Hyseq, its Affiliates, or its Sublicensees in the Territory:

      (a) a Royalty rate of [***] of that portion of annual Net Sales in the
Territory of each such Licensed Product that is less than or equal to [***];

      (b) a Royalty rate of [***] of that portion of annual Net Sales in the
Territory of each such Licensed Product that is greater than [***] and less than
or equal to [***]; and

      (c) a Royalty rate of [***] of that portion of annual Net Sales in the
Territory of each such Licensed Product that is greater than [***].

      5.3 [***] Hyseq acknowledges that Hyseq may be obligated to pay Third
Party Payments to [***] for licensing of [***] technology with respect to
Licensed Products, in addition to the Milestone Payments set forth in Section
5.1 and the Royalties set forth in Section 5.2 above. Such payments shall be
non-creditable against any payments due to Amgen under this License Agreement.

      5.4 THIRD PARTY ROYALTY REDUCTION. Hyseq shall be responsible for
obtaining any licenses, and for making any Third Party Payments thereunder, or
making any then-due Third Party Payments to Amgen (for forwarding to the
licensing Third Party) under any sublicenses granted by Amgen hereunder, for
rights to any Third Party intellectual property required to make, have made,
use, sell, lease, offer to sell or lease, have sold, import, export or otherwise
exploit, or transfer physical possession of or title in, a Licensed Product in
one or more countries in the Territory. [***] if, and for so long as Hyseq is
required to pay such Third Party royalties for such license, [***] of the
royalties which are payable by Hyseq shall be creditable by Hyseq against any
Royalties due to Amgen under Section 5.2 above for the Net Sales of such
Licensed Product in such country, provided however, that, on a Licensed
Product-by-Licensed Product basis, Hyseq's Royalty rate set forth in Section 5.2
in any given year will not be reduced in excess of [***] as a consequence of any
royalties being creditable against the Royalties to be paid to Amgen by Hyseq.
Hyseq shall have sole discretion, authority and right with respect to
determining whether to enter into an agreement for a license or other rights and
to incur an obligation for any Third Party Payments.

      5.5 COMPETITION REDUCTION. If, and for so long as one or more Competitive
Product(s) shall be commercially available in a country in the Territory and
shall have in the aggregate a share of more than [***] of the total market of
all Licensed Product(s) in that country as measured by sales units (based on
data provided by IMS International, or if such data shall not be available,
based on such other data mutually agreed to by Amgen and Hyseq), Hyseq shall
have the immediate right to reduce the Royalty rates on Net Sales of each such
Licensed Product(s) in such country by [***] of those set forth in Section 5.2.

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<PAGE>

      5.6 TERM OF ROYALTIES. Amgen's right to receive Royalties under Section
5.2 shall expire, on a Licensed Product-by-Licensed Product basis and
country-by-country basis, upon the later of: (a) [***] each such Licensed
Product; or (b) the expiration of the last-to-expire of the Amgen Patent Rights
and (subject to the following sentence) Joint Patent Rights containing an issued
Valid Claim that, but for the license granted by Amgen to Hyseq, would be
infringed by the use or sale by Hyseq, its Affiliates and Sublicensees of such
Licensed Product in such country. Where the Joint Patent Rights described in
subparagraph (b) subsist after expiry of the Amgen Patent Rights, then upon such
expiry the Royalties payable pursuant to Section 5.2 (as reduced by Sections 5.4
and 5.5, as applicable) [***], and shall continue to be payable by Hyseq if:

      (i) [***], or

      (ii) Hyseq has elected to continue to retain its exclusive rights to such
subsisting Joint Patent Rights,

but failing which Hyseq's obligation to pay all Royalties shall expire and each
Party shall thereafter be free to use and exploit their respective interest in
the Joint Patent Rights without the obligation to obtain the consent of, or to
account to, the other Party. Notwithstanding any of the foregoing, after
expiration of Amgen's right to receive Royalties for at least one Licensed
Product (i.e. the first Licensed Product), Amgen's right to receive Royalties
for any subsequent Licensed Product shall be determined solely by subparagraph
(b) above and not by subparagraph (a).

      5.7 SUBLICENSING IN ASIAN COUNTRIES. In the event of a sublicensing by
Hyseq to a Third Party of the right to Develop and/or Commercialize Licensed
Products in Asian Countries, Amgen [***]. In all other regions, Hyseq shall
remain responsible for all other rights and obligations under this License
Agreement, including making all payments to Amgen in accordance with Sections
5.1 and 5.2 and in guaranteeing the performance of such Sublicensee for all
other obligations to Amgen.

                                    ARTICLE 6
                              INTELLECTUAL PROPERTY

      6.1 TECHNOLOGY OWNERSHIP. Ownership of inventions shall be determined in
accordance with the rules of inventorship under United States patent laws.
Subject to the licenses granted in Section 2.1, as between the Parties, Amgen
shall own all right, title and interest in and to Amgen Technology, and any
Confidential Information contained therein shall be considered the Confidential
Information of Amgen. As between the Parties, all right and interest in and to
Joint Know-How (which shall be considered the joint Confidential Information of
the Parties) and Joint Patent Rights shall be owned jointly by Hyseq and Amgen,
and shall be subject to the license granted to Hyseq in Section 2.1.

      6.2 PROSECUTION.

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      (a) At its own cost and expense, Amgen will be responsible (using mutually
acceptable outside counsel) for the filing, prosecution, defense and maintenance
of Amgen Patent Rights before all patent authorities in the Territory. [***]
such filing, prosecution and defense of the Amgen Patent Rights by Amgen and
[***] Amgen shall [***]. To that end, Amgen shall instruct such outside counsel
to furnish Hyseq with a reasonably complete draft of each potential submission
to a patent authority regarding Amgen Patent Rights no later than [***] (or if
given less than [***] to respond as soon as practicable) prior to the date such
submission is proposed to be made, and shall [***] thereon. Additionally, Amgen
shall instruct such outside counsel to provide Hyseq with a copy of each
submission made to and document received from a patent authority regarding any
Amgen Patent Rights reasonably promptly after making such filing or receiving
such document. If Amgen determines in its sole discretion to not file,
prosecute, defend or maintain any claim or patent application or patent within
Amgen Patent Rights in any country, then Amgen shall provide Hyseq with [***]
prior written notice of such determination to provide Hyseq with the right and
opportunity to file, prosecute and maintain such claim or patent application or
patent on behalf of Amgen (at Hyseq's sole cost and expense).

      (b) At its own cost and expense, Hyseq will be responsible (using mutually
acceptable outside counsel) for the filing, prosecution, defense and maintenance
of Joint Patent Rights before all patent authorities in the Territory. [***]
such filing, prosecution and defense of the Joint Patent Rights by Hyseq and
[***], Hyseq shall [***]. To that end, Hyseq shall instruct such outside counsel
to furnish Amgen with a reasonably complete draft of each potential submission
to a patent authority regarding Joint Patent Rights no later than [***] (or if
given less than [***] to respond as soon as practicable) prior to the date such
submission is proposed to be made, and shall [***]thereon. Additionally, Hyseq
shall instruct such outside counsel to provide Amgen with a copy of each
submission made to and document received from a patent authority regarding any
Joint Patent Rights reasonably promptly after making such filing or receiving
such document. If Hyseq determines in its sole discretion to not file,
prosecute, defend or maintain or any claim or patent application or patent
within Joint Patent Rights in any country, then Hyseq shall provide Amgen with
[***] prior written notice of such determination to provide Amgen with the right
and opportunity to file, prosecute, defend and maintain such claim or patent
application or patent on behalf of both Parties (at Amgen's sole cost and
expense).

      (c) Amgen and Hyseq shall each provide to the other any invention
disclosures submitted to its respective outside or in-house patent counsel in
the normal course of its business which disclose an invention within Amgen
Know-How and Joint Know-How, respectively. Amgen and Hyseq shall cooperate with
each other and render all reasonable assistance in prosecuting and maintaining
all intellectual property licensed under this License Agreement. Both Parties
shall meet regularly, but not less than on a [***] basis, to discuss the
prosecution (and other related proceedings, such as interferences and
oppositions) of all intellectual property licensed under this License Agreement.
Amgen and Hyseq shall cooperate with each other in any such matters, and shall
sign any necessary legal papers and provide the Party responsible for such
prosecution with data or other information in support thereof (and use their
[***] to ensure the cooperation of any of their respective personnel and, in the
case of Hyseq, it's Affiliates and licensee(s) as might reasonably be
requested).

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      (d) Hyseq shall be responsible (using mutually acceptable outside counsel)
for the filing, prosecution, defense and maintenance of the Product Trademarks
before all trademark authorities in the Territory. For the Product Trademarks
solely or jointly owned by Amgen, Amgen shall have the [***] on such filing,
prosecution and defense of the Product Trademarks by Hyseq and [***] and Hyseq
shall [***]. To that end, Hyseq shall instruct such outside counsel to furnish
Amgen with a reasonably complete draft of each submission to a trademark
authority regarding the Product Trademarks no later than [***] prior to the date
such submission is proposed to be made, or if given less than [***] to respond
as soon as practicable, and Hyseq will [***]thereon. Additionally, Hyseq shall
instruct such outside counsel to provide Amgen with a copy of each submission
made to or document received from a trademark authority regarding any Product
Trademarks reasonably promptly after making such filing or receiving of such
document. If Hyseq determines in its sole discretion to not file, prosecute,
defend or maintain a Product Trademark in any country, then Hyseq shall provide
Amgen with [***] prior written notice of such determination and shall provide
Amgen with the right and opportunity to file, prosecute, defend and maintain
such Product Trademark on behalf of Hyseq.

      6.3 INFRINGEMENT OF PATENTS AND TRADEMARKS BY THIRD PARTIES.

      (a) At its own cost and expense, Amgen may, but shall not be obligated to,
elect to enforce Amgen Patent Rights against any actual, alleged or threatened
infringement by Third Parties and to defend the Amgen Patent Rights against any
challenges in the Territory. In the event Amgen shall so elect to enforce Amgen
Patent Rights against a Third Party infringement which may in any way affect the
rights conferred to Hyseq pursuant to this License Agreement to Develop,
manufacture and Commercialize Licensed Products, Amgen shall [***] and Hyseq, at
Amgen's request [***]. If Amgen finds it necessary or desirable to [***], at the
expense of Amgen. In the event Amgen does not commence an enforcement and/or
defense action pursuant to this Section 6.3(a) within [***] after Hyseq notifies
Amgen or is notified by Amgen in writing of an actual, alleged or threatened
infringement by a Third Party of the Amgen Patent Rights in the Territory (or of
the filing of a declaratory judgment action) which may in any way affect the
rights conferred to Hyseq pursuant to this License Agreement to Develop,
manufacture and Commercialize Licensed Products, Hyseq shall be entitled to
bring and prosecute such an action at its own cost and expense. If Hyseq elects
to bring and prosecute such an action, then Hyseq shall [***], and Amgen (at
Hyseq's request [***]. If Hyseq finds it necessary or desirable to [***] at
Hyseq's expense. Amgen shall, at its own expense, be entitled to participate in
and to have counsel selected by it participate in any action in which Amgen is a
named party.

      (b) At its own cost and expense, Hyseq may, but shall not be obligated to,
elect to enforce Joint Patent Rights against any actual, alleged or threatened
infringement by Third Parties and to defend the Joint Patent Rights against any
challenges in the Territory. In the event Hyseq shall so elect, Hyseq shall
[***], and Amgen (at Hyseq's request [***]. If Hyseq finds it necessary or
desirable to [***] at the expense of Hyseq. In the event Hyseq does not commence
an enforcement and/or defense action pursuant to this Section 6.3(b) within
[***] after Amgen notifies Hyseq or is notified by Hyseq in writing of an
actual, alleged or threatened infringement by a Third Party of the Joint Patent
Rights in the Territory (or of the filing of a declaratory judgment action),
Amgen shall be entitled to bring and prosecute such an action at its own cost
and expense. If Amgen elects to bring and prosecute such an action, then Amen
shall [***] on

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[***], and Hyseq (at Amgen's request [***]. If Amgen finds it necessary or
desirable to [***]at Amgen's expense. Hyseq shall, at its own expense, be
entitled to participate in and to have counsel selected by it participate in any
action in which Hyseq is a named party.

      (c) At its own cost and expense, Hyseq may, but shall not be obligated to,
elect to enforce the Product Trademarks against Third Parties and to defend the
Product Trademarks against any challenges in the Territory. Hyseq shall [***]
determining the strategy and Amgen, at Hyseq's request [***] in any such
enforcement or defense. If Hyseq finds it necessary or desirable to [***] at the
expense of Hyseq. In the event Hyseq does not commence an enforcement and/or
defense action pursuant to this Section 6.3(c) within [***] after Amgen notifies
or is notified by Hyseq in writing of an infringement of the Product Trademarks
in the Territory (or of the filing of a declaratory judgment action, in the case
of defense actions), Amgen shall be entitled to bring and prosecute such an
action at its own cost and expense. If Amgen elects to bring and prosecute such
an action, then Amen shall [***] on and Hyseq, at Amgen's request [***]
in any such enforcement or defense. If Amgen finds it necessary or desirable to
[***] at Amgen's expense. Hyseq shall, at its own expense, be entitled to
participate in and to have counsel selected by it participate in any action in
which Hyseq is a named party.

      (d) Any recovery realized as a result of any such litigation described in
this Section 6.3 (after reimbursement of the Parties' reasonable attorneys' fees
for outside counsel and litigation expenses) shall be allocated [***].

      (e) Neither Party shall enter into any settlement of any suit brought
under this Section 6.3 [***].

      (f) A Party bringing suit under this Section 6.3 shall notify the other
Party of all substantive developments with respect to such enforcement or
defensive actions including, but not limited to, all material filings, court
papers and other related documents, substantive settlement negotiations and
offers of settlement.

      (g) Each Party shall promptly notify the other upon becoming aware of any
Third Party infringement of the Amgen Patent Rights, Joint Patent Rights,
Product Trademarks, Amgen Know-How or Joint Know-How.

      6.4 INFRINGEMENT OF THIRD PARTY RIGHTS.

      (a) At its own cost and expense, Hyseq shall have the first right to
defend any action naming Hyseq, or both Parties, and claiming the infringement
of (i) any Third Party Patent Rights or other intellectual property rights
through the making, having made, using, selling, offering to sell or having
sold, importing, exporting or otherwise exploiting, transferring possession of
title or interest in, Licensed Product, or (ii) any Third Party Trademark
through the Development, manufacturing or Commercialization of a Licensed
Product. The Parties shall [***] during the defense of any such action. At
Hyseq's cost and expense, Amgen shall [***]. If Hyseq finds it necessary or
desirable to [***] at Hyseq's expense. Subject to the foregoing,

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Amgen shall, at its own expense, be entitled to participate in and to have
counsel selected by it participate in any action in which Amgen is a named
party.

      (b) Each Party shall promptly notify the other upon becoming aware of any
actual, alleged or threatened Third Party claim or action against Hyseq and/or
Amgen for infringement of any Third Party Trademark through the Development,
manufacturing or Commercialization of a Licensed Product; or any Third Party
Patent Rights through the making, having made, using, selling, offering to sell,
and importing, exporting or otherwise transferring physical possession of or
otherwise transferring title in and to Licensed Products in the Territory.

      (c) Neither Party shall enter into any settlement of any suit referenced
under this Section 6.4 that [***].

      (d) A Party defending suit under this Section 6.4 shall notify the other
Party of all substantive developments with respect to such enforcement or
defensive actions including, but not limited to, all material filings, court
papers and other related documents, substantive settlement negotiations and
offers of settlement.

      6.5 EMPLOYEE OBLIGATIONS. Prior to beginning work relating to any aspect
of the subject matter of this License Agreement and/or being given access to
Amgen Know-How or Joint Know-How or the Confidential Information of the other
Party, each employee, consultant or agent of Hyseq and Amgen shall have signed
or shall be required to sign a non-disclosure and invention assignment agreement
pursuant to which each such person shall agree to comply with all of the
obligations of Hyseq or Amgen, as appropriate, substantially including: (a)
promptly reporting any invention, discovery, process, software program or other
intellectual property right, as appropriate within Amgen Know-How or Joint
Know-How; (b) assigning to Hyseq or Amgen, as appropriate, all of his or her
right, title and interest in and to any such invention, discovery, process,
software program or other intellectual property right; (c) cooperating in the
preparation, filing, prosecution, maintenance and enforcement of any Patent
Rights; (d) performing all acts and signing, executing, acknowledging and
delivering any and all papers, documents and instruments required for effecting
the obligations and purposes of this License Agreement; and (e) abiding by the
obligations of confidentiality and non-use set forth in this License Agreement.
It is understood and agreed that any such non-disclosure and invention
assignment agreement need not be specific to this License Agreement.

      6.6 PATENT MARKING. Licensed Products marketed and sold by Hyseq hereunder
shall be marked with appropriate patent numbers or indicia of Amgen Patent
Rights and/or Joint Patent Rights to the extent permitted by law in those
countries of the Territory in which such markings have notice value as against
infringers of patents.

      6.7 [***].

      (a) Hyseq, on behalf of itself and its directors, employees, officers,
shareholders, agents, successors and assigns [***]Amgen, its directors,
employees, officers, shareholders, agents, successors and assigns, [***].

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      (b) Amgen, on behalf of itself and its directors, employees, officers,
shareholders, agents, successors and assigns [***] Hyseq, its directors,
employees, officers, shareholders, agents, successors and assigns, [***].

                                    ARTICLE 7
                            PAYMENTS; RECORDS; AUDIT

      7.1 PAYMENTS.

      (a) U.S. Dollars. All payments to be made under this License Agreement
shall be made in United States Dollars by bank wire transfer in immediately
available funds to a bank account designated from time-to-time by Amgen.

      (b) Royalty Payments. All Royalties payable to Amgen under this License
Agreement shall be paid within [***] of the end of each Calendar Quarter except
as otherwise specifically provided herein. Each payment of Royalties owing to
Amgen shall be accompanied by a statement certified by an executive officer of
Hyseq as accurate to the best of its ability consistent with Hyseq's standard
practices in performing such computations and in accordance with GAAP, (i) on a
country-by-country basis, of the amount of gross sales of Licensed Products, an
itemized calculation of Net Sales of each Licensed Product during such Calendar
Quarter, (ii) the amount of aggregate worldwide gross sales of Licensed Product
and Net Sales during such Calendar Quarter and (iii) on a cumulative basis for
the current year and the amount of Royalty due on Net Sales during such Calendar
Quarter.

      (c) Foreign Exchange. Net Sales received in currencies other than United
States Dollars shall be converted into the United States Dollar equivalent, at
the average rate of exchange for the Calendar Quarter to which such payments
relate, as reported in Bloomberg Professional, a service of Bloomberg L.P.,
during the Royalty period of such Net Sales, or in the event Bloomberg
Professional is not available then The Wall Street Journal.

      (d) Late Payments. Any amounts not paid by Hyseq when due under this
License Agreement shall be subject to interest from and including the date
payment is due through and including the date upon which Hyseq has made a wire
transfer of immediately available funds into an account designated by Amgen of
such payment at a rate equal to the lesser of (i) the sum of [***] plus the
annual prime rate or successive annual prime rates of interest quoted in the
Money Rates section of the on-line edition of the Wall Street Journal (at
http://www.interactive.wsj.com) calculated daily on the basis of a 365-day year
or (ii) the highest rate permitted by applicable law.

      (e) Blocked Currency. If Hyseq, its Affiliates and/or Sublicensees are
unable to convert a foreign currency into United States Dollars for reasons
beyond their respective control, or are restricted by law or regulation from
remitting Royalties from any country of sale, Hyseq shall cause such payment to
be made by deposit to the credit and account of Amgen or its designated nominee
in any commercial bank designated by Amgen in the applicable country. Hyseq
shall deliver to Amgen proper evidence of such deposit.

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      (f) Withholding Taxes. Any taxes, assessments and fees to be withheld by
Hyseq under the laws, rules or regulations of any foreign country for the
account of Amgen shall be promptly paid by Hyseq for and on behalf of Amgen to
the appropriate governmental authority, and Hyseq shall furnish Amgen with a
copy of the original official receipt for the payment of such tax within [***]
of payment. Any such tax, assessment and fee actually paid on Amgen's behalf
shall be deducted from any Royalty payments due to Amgen. Hyseq agrees to make
all lawful and reasonable efforts to minimize such taxes, assessments and fees
to Amgen.

      7.2 RECORDS; AUDIT. Hyseq shall keep or cause to be kept such records as
are required in sufficient detail to track and determine (in a manner consistent
with GAAP) the accuracy of calculations of all sums or credits due under this
License Agreement and to accurately account for the calculations of all
Royalties due for Licensed Products under this License Agreement. Such records
shall be retained for a period of the later of (i) a [***] period following the
year in which any payments were made hereunder and/or (ii) the expiration of the
applicable tax statute of limitations (or any extensions thereof), or such
longer period as may be required by law. [***] per Calendar Year, Amgen shall
have the option to engage (at its own expense) an independent certified public
accountant, appointed by Amgen and reasonably acceptable to Hyseq, to examine in
confidence the books and records of Hyseq as may be necessary to determine, with
respect to any Calendar Year, the correctness or completeness of any report or
payment required to be made under this License Agreement; provided however, that
the books and records for any particular Calendar Year shall only be subject to
one audit. The report of such accountant shall be limited to a certificate
verifying any report made or payment submitted by Hyseq during such period but
may include, in the event the accountant shall be unable to verify the
correctness of any such payment, information relating to why such payment is
unverifiable. All information contained in any such certificate shall be deemed
the Confidential Information of Hyseq hereunder. If any audit performed under
this Section 7.2 discloses a variance of more than [***] from the amount of the
original report, showing the calculation of a Royalty under section 5.2 of this
License Agreement or calculation of consideration due to Amgen under section 5.7
of this License Agreement, Hyseq shall bear the full cost of the performance of
such audit. Upon the expiration of [***] following the end of any Calendar Year,
the calculation of any such amounts payable with respect to such Calendar Year
shall be binding and conclusive upon Amgen, and Hyseq shall be released from any
liability or accountability with respect to such amounts for such Calendar Year.

                                    ARTICLE 8
                                  PUBLICATIONS

      8.1 PROCEDURE. Hyseq shall determine the overall strategy for and have the
right of publishing and presenting results of pre-clinical and clinical studies
of Licensed Products. However, each Party to this License Agreement recognizes
that the publication of papers regarding results of and other information
involving the activities under this License Agreement (including oral
presentations and abstracts) may be beneficial to both Parties, provided such
publications are subject to reasonable controls to protect Confidential
Information. In particular, it is the intent of the Parties to maintain the
confidentiality of any Confidential Information included in any patent
application until such patent application has been published. Accordingly, Amgen
will have the right to review and approve any paper proposed for publication by
Hyseq

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(including oral presentations and abstracts) which utilizes Confidential
Information of Amgen. Before any such paper is submitted for publication or an
oral presentation made, Hyseq will deliver a complete copy of the paper or
materials and abstracts for oral presentation to Amgen at least [***] prior to
submitting the paper to a publisher or making the presentation. Amgen will
review any such paper and give its comments to Hyseq within [***] after the
delivery of such paper to Amgen. With respect to oral presentation materials and
abstracts, Amgen will make reasonable efforts to expedite review of such
materials and abstracts and will return such items as soon as practicable to
Hyseq with appropriate comments, if any, but in no event later than [***] from
the date of delivery to Amgen. Hyseq will comply with Amgen's request to delete
references to Amgen's Confidential Information in any such paper and agrees to
withhold publication of same for an additional [***] in order to permit the
Parties to obtain patent protection, if either of the Parties deems it
necessary, in accordance with the terms of this License Agreement. Hyseq will
have the right to review and approve any paper proposed for publication by Amgen
(including oral presentations and abstracts) which describes Licensed Products
or which includes Confidential Information of Hyseq. Before any such paper is
submitted for publication or an oral presentation made, Amgen will deliver a
complete copy of the paper or materials and abstracts for oral presentation to
Hyseq at least [***] prior to submitting the paper to a publisher or making the
presentation. Hyseq will review any such paper, materials and abstracts and give
its comments to Amgen within [***] after the delivery of such paper to Hyseq.
With respect to oral presentation materials and abstracts, Hyseq will make
reasonable efforts to expedite review of such materials and abstracts and will
return such items as soon as practicable to Amgen with appropriate comments, if
any, but in no event later than [***] from the date of delivery to Hyseq. Amgen
will comply with Hyseq's request to delete references to Hyseq's Confidential
Information in any such paper and agrees to withhold publication of same for an
additional [***]in order to permit the Parties to obtain patent protection, if
either of the Parties deems it necessary, in accordance with the terms of this
License Agreement.

      8.2 CREDIT. Any such publication or presentation will include recognition
of the contributions of the other Party according to standard practice for
assigning scientific credit, either through authorship or acknowledgment as may
be appropriate.

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                                    ARTICLE 9
                                 CONFIDENTIALITY

      9.1 TREATMENT OF CONFIDENTIAL INFORMATION. The Parties agree that during
the Term, and for a period of [***] after this License Agreement expires or
terminates, a Party receiving Confidential Information of the other Party shall
(a) maintain such Confidential Information in confidence to the same extent such
Party maintains its own confidential or proprietary information or trade secrets
of similar kind and value (but at a minimum each Party shall use [***] to
maintain such Confidential Information in confidence); (b) not disclose such
Confidential Information to any Third Party without the prior written consent of
the disclosing Party, except for disclosures to its Affiliates and Sublicensees
who agree to be bound by obligations of non-disclosure and non-use at least as
stringent as those contained in this Article 9; and (c) not use such
Confidential Information for any purpose except those purposes permitted by this
License Agreement. Neither Party shall knowingly disclose to the other Party any
Third Party information or know-how that such Party does not have the legal
right to disclose to the other Party and/or which it has a contractual
obligation not to disclose to the other Party.

      9.2 AUTHORIZED DISCLOSURE. Notwithstanding any other provision of this
License Agreement, each Party may disclose Confidential Information of the other
Party:

      (a) to the extent and to the persons and entities as required by an
applicable law, rule, regulation, legal process, court order or the rules of the
National Association of Securities Dealers or of a Regulatory Authority; or

      (b) as necessary to file, prosecute or defend those patent applications or
patents for which either Party has the right to assume filing, prosecution,
defense or maintenance, pursuant to Section 6.2 of this License Agreement; or

      (c) to prosecute or defend litigation or otherwise establish rights or
enforce obligations under this License Agreement, but only to the extent that
any such disclosure is necessary.

The Party required or intending to disclose the other Party's Confidential
Information under Sections 9.2(a) or (c) shall first have given prompt notice to
the other Party to enable it to seek any available exemptions from or
limitations on such disclosure requirement and shall reasonably cooperate in
such efforts by the other Party.

      9.3 MATERIALS. Pursuant to Section 16.9(c) of the Collaboration Agreement,
the Parties anticipate that Amgen may transfer certain of its Amgen Know-How and
Amgen Material and Manufacturing Information to Hyseq; provided however, that
Hyseq agrees and acknowledges that Amgen may, but shall be under no obligation,
to transfer any Amgen Know-How and Amgen Material and Manufacturing Information
characterized, conceived, developed, derived, generated or identified by Amgen
after the Effective Date. Hyseq agrees that it shall use such Amgen Know-How and
Amgen Material and Manufacturing Information only in accordance with the terms
and conditions of this License Agreement and will transfer such Amgen Know-How
and Amgen Material and Manufacturing Information only to a Third Party

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<PAGE>

which has agreed in writing to be bound by obligations of confidentiality and
non-use at least as restrictive as set forth herein and only to use in
accordance with the terms of this License Agreement. Hyseq will promptly
thereafter provide notice of such transfer to Amgen.

      9.4 PUBLICITY; TERMS OF AGREEMENT. The Parties agree that the existence of
and the material terms of this License Agreement shall be considered
Confidential Information of both Parties, subject to the special authorized
disclosure provisions set forth below in this Section 9.4 (in lieu of the
authorized disclosure provisions set forth in Section 9.2, to the extent of any
conflict) and without limiting the generality of the definition of Confidential
Information. The Parties will mutually agree upon the text of a press release
announcing the execution of this License Agreement. Thereafter, if either Party
desires to make a public announcement concerning this License Agreement or the
terms hereof that differs from this mutually agreed upon text, such Party shall
give reasonable prior advance notice of the proposed text of such announcement
to the other Party for its prior review and approval, such approval not to be
unreasonably withheld or delayed. A Party shall not be required to seek
permission from the other Party to repeat any information as to the terms of
this License Agreement that have already been publicly disclosed by such Party,
in accordance with the foregoing, or by the other Party. Either Party may
disclose the terms of this License Agreement to potential investors who agree to
be bound by obligations of non-disclosure and non-use at least as stringent as
those contained in this Article 9. The Parties acknowledge that Amgen and/or
Hyseq may be obligated to file a copy of this License Agreement with the U.S.
Securities and Exchange Commission (the "SEC") with its next quarterly report on
Form 10-Q, annual report on Form 10-K or current report on Form 8-K or with any
registration statement filed with the U.S. Securities and Exchange Commission
pursuant to the Securities Act of 1933, as amended, and each such Party shall be
entitled to make such filing; provided however, that it requests confidential
treatment of the more sensitive terms hereof to the extent such confidential
treatment is reasonably available to the filing Party under the circumstances
then prevailing. In the event of any such filing, the filing Party will provide
the non-filing Party with an advance copy of the License Agreement marked to
show provisions for which the filing Party intends to seek confidential
treatment and shall reasonably consider the non-filing Party's timely comments
thereon.

      9.5 USE OF NAMES, LOGOS OR SYMBOLS. Subject to the licenses granted under
Section 2.2, and further subject to the authorized disclosure provisions under
Sections 9.2(a) and 9.4, no Party hereto shall use the name, Trademarks,
physical likeness, employee names or owner symbol of any other party for any
purpose (including, without limitation, private or public securities placements)
without the prior written consent of the affected Party, such consent not to be
unreasonably withheld or delayed so long as such use of name is limited to
objective statement of fact rather than for endorsement purposes. Hyseq shall
not use any Trademark either substantially resembling or which is confusingly
similar to any of Amgen's Trademarks in connection with the subject matter of
this License Agreement.

                                   ARTICLE 10
                         REPRESENTATIONS AND WARRANTIES

      10.1 REPRESENTATIONS AND WARRANTIES OF HYSEQ. Hyseq hereby represents and
warrants to Amgen that as of the Effective Date of the Collaboration Agreement:

                                       16
<PAGE>

      (a) Corporate Existence, Power and Authority. It is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Nevada and has full corporate power and authority and the legal right to own and
operate its property and assets and to carry on its business as it is now being
conducted and as contemplated in this License Agreement and to perform its
obligations hereunder including, without limitation the right to grant the
licenses granted hereunder. It has taken all necessary corporate action on its
part required to authorize the execution and delivery of this License Agreement
and the performance of its obligations hereunder.

      (b) Binding Agreement. This License Agreement has been duly executed and
delivered on behalf of Hyseq and constitutes a legal, valid and binding
obligation of Hyseq that is enforceable against it in accordance with its terms.

      (c) No Conflict. The execution, delivery and performance of this License
Agreement by Hyseq does not conflict with and would not result in a breach of
any agreement, instrument or understanding, oral or written, to which it is a
party or by which it may be bound, nor does it violate any material law or
regulation of any court, governmental body or administrative or other agency
having jurisdiction over it.

      (d) Validity. It is aware of no action, suit, inquiry or investigation
instituted by any Third Party which questions or threatens the validity of this
License Agreement.

      (e) [***]. In entering into this License Agreement, Hyseq has [***].

      (f) Business [***]. It is not in violation of its charter, bylaws, or any
other organizational document, or in violation of any law, administrative
regulation, ordinance or order of any court or governmental agency, arbitration
panel or authority applicable to it, [***]. Except as may be set forth in any
documents required to be filed by it under the Securities Act or Exchange Act,
as the case may be, [***].

      10.2 REPRESENTATIONS AND WARRANTIES OF AMGEN. Amgen hereby represents and
warrants to Hyseq that as of the Effective Date of the Collaboration Agreement:

      (a) Corporate Existence, Power and Authority. It is a corporation duly
organized, validly existing and in good standing under the laws of the State of
Delaware and has full corporate power and authority and the legal right to own
and operate its property and assets and to carry on its business as it is now
being conducted and as contemplated in this License Agreement and to perform its
obligations hereunder including, without limitation, the right to grant the
licenses granted hereunder. It has taken all necessary corporate action on its
part required to authorize the execution and delivery of this License Agreement
and the performance of its obligations hereunder.

      (b) Binding Agreement. This License Agreement has been duly executed and
delivered on behalf of Amgen and constitutes a legal, valid and binding
obligation of Amgen that is enforceable against it in accordance with its terms.

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      (c) No Conflict. The execution, delivery and performance of this License
Agreement by Amgen does not conflict with and would not result in a breach of
any agreement, instrument or understanding, oral or written, to which it is a
party or by which it may be bound, nor does it violate any material law or
regulation of any court, governmental body or administrative or other agency
having jurisdiction over it.

      (d) Validity. It is aware of no action, suit, inquiry or investigation
instituted by any Third Party which questions or threatens the validity of this
License Agreement.

      (e) Business [***]. It is not in violation of its charter, bylaws, or any
other organizational document, or in violation of any law, administrative
regulation, ordinance or order of any court or governmental agency, arbitration
panel or authority applicable to it, [***]. Except as may be set forth in any
documents filed with the Securities and Exchange Commission, as required to be
filed by it under the Securities Act or Exchange Act, as the case may be, [***].

      10.3 MUTUAL COVENANTS. Each Party hereby covenants to the other Party as
follows:

      (a) No Conflict. It shall not during the term of this License Agreement
grant any right, license, consent or privilege to any Third Party(ies) in the
Territory which would conflict with the rights granted to the other Party under
this License Agreement, and shall not take any action that would in any way
prevent it from assuming its obligations or granting the rights granted to the
other Party under this License Agreement or that would otherwise materially
conflict with or adversely affect its obligations or its assumption of the
rights granted to the other Party under this License Agreement.

      (b) [***] It shall work [***] with the other Party with respect to
Licensed Products (subject to Hyseq's rights under Sections 2.3 and 4.1 of this
License Agreement to grant sublicenses to Third Parties). It shall not, directly
or indirectly, make, have made, use, sell, offer to sell, import, export or
otherwise transfer physical possession of or otherwise transfer title in (for
purposes of Developing, manufacturing or Commercializing) a [***] Product in the
Territory, nor license or otherwise enable a Third Party to take such actions
during the Term. [***].

      (c) Regulatory Data. It shall store and provide the other Party access to
source data supporting all Regulatory Filings and Regulatory Approvals for the
longer of (i) [***] or (ii) the time period required by any applicable
Regulatory Authority in the Territory. [***] of the first Licensed Product, it
shall also make its employees, consultants and agents reasonably available upon
reasonable notice from the other Party to consult with the other Party on issues
relating to Licensed Products or relating to requests regarding Licensed
Products from any Regulatory Authority in the Territory.

      10.4 COVENANTS OF HYSEQ.

      (a) No Debarment. In the course of the Development, manufacture and
Commercialization of Licensed Products and during the Term, Hyseq shall not
knowingly use

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and shall not have knowingly used any employee or consultant who is or has been
debarred by a Regulatory Authority or, to the best of Hyseq's knowledge, is or
has been the subject of debarment proceedings by a Regulatory Authority.

      (b) Compliance. Hyseq shall comply with all applicable statutes,
regulations and guidance of Regulatory Authorities in carrying out its
activities regarding the Development, manufacturing and Commercialization of
Licensed Products in the Territory.

      (c) [***]. Hyseq covenants that it shall use [***] Efforts to carry out
its obligations in accordance with the terms of this License Agreement
including, as applicable, the Development, manufacturing and Commercialization
of Licensed Products in the Territory in accordance with the terms of this
License Agreement. Without limiting the generality of the foregoing obligation,
Hyseq covenants that:

            (i) Hyseq shall use [***] to administer a Licensed Product to a
patient in a government-approved clinical trial within [***] after the Effective
Date of the Collaboration Agreement. In the event Hyseq fails to administer such
Licensed Product in such time period then, within [***] after the Effective
Date, Hyseq shall either [***] or Amgen may terminate this License Agreement and
Hyseq shall immediately return all rights to Amgen.

            (ii) Hyseq shall use [***] to administer a Licensed Product to a
patient in a government-approved clinical trial within [***] after the Effective
Date of the Collaboration Agreement. In the event Hyseq fails to administer such
Licensed Product in such time period then, in addition to [***] that [***] under
subsection (i) above and within [***] after the Effective Date, in addition to
the [***] in subsection (i) above, Hyseq will either [***] a [***] or Amgen may
terminate this License Agreement and Hyseq shall immediately return all rights
to Amgen.

            (iii) Hyseq shall use [***] to administer a Licensed Product to a
patient in a government-approved clinical trial within [***] after the Effective
Date of the Collaboration Agreement. In the event Hyseq fails to administer such
Licensed Product in such time period, then Amgen shall have the right to
terminate this License Agreement and Hyseq shall immediately return all rights
to Amgen.

      (d) No Misappropriation. It shall not knowingly misappropriate the trade
secret of a Third Party in its activities to Develop, manufacture or
Commercialize Licensed Products.

      10.5 DISCLAIMERS. EXCEPT AS EXPRESSLY PROVIDED HEREIN, THE MATERIALS AND
INFORMATION PROVIDED HEREUNDER ARE BEING PROVIDED "AS IS" AND WITHOUT ANY
REPRESENTATIONS OR WARRANTIES. NEITHER PARTY MAKES ANY REPRESENTATIONS OR
WARRANTIES, EXPRESS OR IMPLIED, OF ANY TYPE WHATSOEVER REGARDING THE MATERIALS
AND INFORMATION. EACH PARTY EXPRESSLY DISCLAIMS ANY WARRANTY OF MERCHANTABILITY,
OF FITNESS FOR A PARTICULAR PURPOSE OR OF NONINFRINGEMENT.

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                                   ARTICLE 11
                                 INDEMNIFICATION

      11.1 INDEMNIFICATION BY AMGEN. Amgen hereby agrees to defend, hold
harmless and indemnify (collectively "Indemnify" or be "Indemnified") Hyseq and
its Affiliates, agents, directors, officers and employees (the "Hyseq
Indemnitees") from and against any and all Losses resulting directly or
indirectly from any Third Party claims, suits, actions or demands arising
directly or indirectly out of (a) any of Amgen's representations and warranties
set forth in this License Agreement being untrue in any material respect when
made and/or (b) any material breach or material default by Amgen of its
covenants and obligations under this License Agreement. To be eligible to be so
Indemnified as described in this Section 11.1, the Hyseq Indemnitees shall
provide Amgen with prompt notice of any claims, suits, actions or demands (with
a description of the claim and the nature and amount of any such Loss) giving
rise to the indemnification obligation pursuant to this Section 11.1 and the
exclusive ability to defend such claims, suits, actions or demands (with the
reasonable cooperation of Hyseq Indemnitees); provided however, that Amgen shall
be relieved of its obligations only if any failure by the Hyseq Indemnitee to
deliver prompt notice shall have been prejudicial to its ability to defend such
claims, suits, actions or demands. Hyseq shall have the right to retain its own
counsel, at its own expense, if representation of the counsel of Amgen would be
inappropriate due to actual or potential differing interests between the
Parties. Amgen shall not settle or consent to the entry of any judgment with
respect to any claim for Loss for which indemnification is sought, [***].
Amgen's obligation to Indemnify the Hyseq Indemnitees pursuant to this Section
11.1 shall not apply to the extent of any Losses (i) that arise from the [***]
of any Hyseq Indemnitee; (ii) that arise from Hyseq's material breach of any
representation, warranty, covenant or obligation under this License Agreement;
or (iii) for which Hyseq is obligated to Indemnify the Amgen Indemnitees
pursuant to Section 11.2 of this License Agreement.

      11.2 INDEMNIFICATION BY HYSEQ. Hyseq hereby agrees to Indemnify Amgen and
its Affiliates, agents, directors, officers and employees (the "Amgen
Indemnitees") from and against any and all Losses arising from Third Party
claims, suits, actions or demands resulting directly or indirectly from (a) any
of Hyseq's representations and warranties set forth in this License Agreement
being untrue in any material respect when made; (b) the Development, manufacture
and Commercialization of Licensed Products by, on behalf of or under authority
of Hyseq, its Affiliates or its Sublicensees; and/or (c) any material breach or
material default by Hyseq of its covenants and obligations under this License
Agreement. To be eligible to be Indemnified as described above in this Section
11.2, the Amgen Indemnitees shall provide Hyseq with prompt notice of any
claims, suits, actions or demands (with a description of the claim and the
nature and amount of any such Loss) giving rise to the indemnification
obligation pursuant to this Section 11.2 and the exclusive ability to defend
such claims, suits, actions or demands (with the reasonable cooperation of Amgen
Indemnitees); provided however, that Hyseq shall be relieved of its obligations
only if any failure by the Amgen Indemnitee to deliver prompt notice shall have
been prejudicial to its ability to defend such claims, suits, actions or
demands. Amgen shall have the right to retain its own counsel, at its own
expense, if representation of the counsel of Hyseq would be inappropriate due to
actual or potential differing interests between the Parties. Hyseq shall not
settle or consent to the entry of any judgment with respect to any claim for
Loss for

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which indemnification is sought, [***]. Hyseq's obligation to Indemnify the
Amgen Indemnitees pursuant to this Section 11.2 shall not apply to the extent of
any Losses (i) that arise from the [***] of any Amgen Indemnitee (including but
not limited to that arising from the manufacture of Licensed Product by Amgen),
(ii) that arise from any material breach by Amgen of any representation,
warranty, covenant or obligation under this License Agreement or (iii) for which
Amgen is obligated to Indemnify the Hyseq Indemnitees pursuant to Section 11.1
of this License Agreement.

      11.3 INSURANCE. Within [***] of the Effective Date, Hyseq shall at its own
expense procure and maintain an insurance policy/policies, including product
liability insurance (but excluding clinical trial insurance policies which shall
be required only while trials are ongoing), adequate to cover its obligations
hereunder and which is/are consistent with normal business practices of prudent
companies similarly situated. Hyseq may self-insure all or part of any such
obligation consistent with pharmaceutical industry practices but Hyseq shall at
all times maintain the following minimum Third Party insurance coverage:

<TABLE>
<CAPTION>
                 TYPE OF COVERAGE                                AMOUNT
                 ----------------                                ------
<S>                                                              <C>
       Commercial General Liability Insurance                    [***]

       Product Liability Insurance                               [***]

       Excess Liability Insurance                                [***]

       Clinical Trial Liability Insurance                        [***]

       Workman's Compensation                                    [***]
</TABLE>

Each insurance policy required by and procured by Hyseq under this Section 11.3
shall name Amgen as an additional insured. Such insurance shall not be construed
to create a limit of Hyseq's liability with respect to its indemnification
obligations under this Article 11. Hyseq shall provide Amgen with a copy of the
certificate of insurance or other evidence of such insurance and/or
self-insurance, upon request. Hyseq shall provide Amgen with written notice at
least [***] prior to the cancellation, non-renewal or material change in such
insurance or self-insurance which materially adversely affects the rights of
Amgen hereunder.

      11.4 PRE-EFFECTIVE DATE LOSSES. In accordance with Section 16.12 of the
Collaboration Agreement, each Party shall retain its obligations for Losses
accrued under the Collaboration Agreement and this License Agreement shall not
release, waive, alter or otherwise modify the Parties' respective obligations
thereunder. Other than with respect to its obligation for Losses due under and
prior to the termination of the Collaboration Agreement, Hyseq shall not assume
or be liable for (pursuant to this License Agreement) any Losses for which Amgen
is previously responsible, resulting from or arising in connection with the
Development, manufacture or Commercialization of Licensed Product on or prior to
the Effective Date.

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      11.5 LIMITATION OF LIABILITY. NEITHER PARTY NOR ITS RESPECTIVE AFFILIATES
SHALL BE LIABLE FOR SPECIAL, EXEMPLARY, CONSEQUENTIAL OR PUNITIVE DAMAGES,
WHETHER IN CONTRACT, WARRANTY, TORT, STRICT LIABILITY OR OTHERWISE INCURRED BY
THE OTHER PARTY IN CONNECTION WITH THIS LICENSE AGREEMENT, INCLUDING BUT NOT
LIMITED TO DAMAGES MEASURING LOST PROFITS OR BUSINESS OPPORTUNITIES.

                                   ARTICLE 12
                              TERM AND TERMINATION

      12.1 TERM. This License Agreement shall become effective on the Effective
Date and shall remain in full force and effect, unless earlier terminated
pursuant to this Article 12, on a country-by-country basis until there is no
remaining Royalty payment obligation in any country. Upon the expiry of Hyseq's
obligation to pay Royalties under this License Agreement for a given Licensed
Product in a country, Hyseq shall have a fully paid, royalty free, unrestricted
license under the Amgen Technology and the Amgen Material and Manufacturing
Information to make, have made, use, sell, offer to sell, have sold, import,
export and otherwise exploit, transfer physical possession of and transfer title
or interest in or to such given Licensed Product in such country.

      12.2 TERMINATION FOR CONVENIENCE. Hyseq may terminate this License
Agreement at any time by providing [***] prior written notice of termination to
Amgen.

      12.3 TERMINATION BY AMGEN. In the event Hyseq shall not timely [***]
pursuant to either Section 10.4(c)(i) or 10.4(c)(ii) or shall not timely
administer a Licensed Product to a patient pursuant to Section 10.4(c)(iii),
Amgen shall have the sole right to terminate this License Agreement by providing
[***] prior written notification of termination to Hyseq.

      12.4 TERMINATION FOR DEFAULT.

      (a) In the event any material representation or warranty made hereunder or
under the Warrant Purchase Agreement by either Party shall have been untrue in
any material respect ("Representation Default"), or upon any material breach or
material default of a material obligation of this License Agreement or the
Warrant Purchase Agreement (as defined in the Collaboration Agreement) by a
Party ("Performance Default"), the Party not in default ("Non-Defaulting Party")
must first give the other Party ("Defaulting Party") written notice thereof
("Notice of Default"), which notice must state the nature of the Representation
Default or Performance Default in reasonable detail and must request the
Defaulting Party cure such Representation Default or Performance Default within
[***]. During any such [***] period after receipt or delivery of a Notice of
Default under this Section 12.4(a) for which termination of this License
Agreement, in whole or in part is a remedy, all of the Party's respective rights
and obligations under the affected parts of this License Agreement, including
but not limited to Development, manufacturing and Commercialization, shall (to
the extent applicable) remain in force and effect. If the Defaulting Party shall
dispute the existence, extent or nature of any default set forth in a Notice of
Default, the Parties shall use good faith efforts to resolve the dispute.

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      (b) Hyseq. In the event of a Representation Default or a Performance
Default by Hyseq that shall not have been cured within the period set forth in
Section 12.4(a) above after receipt of a Notice of Default (or Hyseq shall not
have presented a reasonably achievable plan to cure such Default as promptly as
is reasonably practicable under the circumstances), Amgen, at its option, may
terminate this License Agreement upon [***]prior written notice, unless such
Representation Default is an unintentional Representation Default of the
Warranty Agreement and Amgen did not provide Notice of Default within [***]after
the Effective Date. In addition, in the event of termination pursuant to such
uncured Representation Default as provided in the foregoing sentence, Amgen will
be entitled to receive a refund of all money paid.

      (c) Amgen. In the event of a Representation Default or a Performance
Default by Amgen that shall not have been cured within the period set forth in
Section 12.4(a) after receipt of a Notice of Default (or Amgen shall not have
presented a reasonably achievable plan to cure such Default as promptly as is
reasonably practicable under the circumstances), Hyseq, at its option, may
terminate this License Agreement upon [***] prior written notice. In addition,
in the event of termination pursuant to such uncured Representation Default as
provided in the foregoing sentence, Hyseq will be entitled to receive a refund
of all money paid.

      12.5 BANKRUPTCY.

      (a) [***] may terminate this License Agreement if, during the term of the
Research Program, [***] shall file in any court or agency pursuant to any
statute or regulation of any state or country, a petition in bankruptcy or
insolvency or for reorganization or for an arrangement or for the appointment of
a receiver or trustee of [***] or of its assets, or if [***] proposes a written
agreement of composition or extension of its debts, or if [***] shall be served
with an involuntary petition in bankruptcy or seeking reorganization,
liquidation, dissolution, winding-up arrangement, composition or readjustment of
its debts or any other relief under any bankruptcy, insolvency, reorganization
or other similar act or law of any jurisdiction now or hereafter in effect, or
there shall have been issued a warrant of attachment, execution, distraint or
similar process against it, filed in any insolvency proceeding, and such
petition shall not be dismissed within ninety (90) days after the filing
thereof, or if [***] shall propose or be a party to any dissolution or
liquidation, or if [***] shall make an assignment for the benefit of creditors.

      (b) All rights and licenses granted under or pursuant to this License
Agreement by [***] are and shall otherwise be deemed to be for purposes of
Section 365(n) of the U.S. Bankruptcy Code, licenses of rights to "intellectual
property" as defined under Section 101 of the U.S. Bankruptcy Code. The Parties
agree that each Party shall retain and may fully exercise all of its rights and
elections under the U.S. Bankruptcy Code. The Parties further agree that, in the
event of the commencement of a bankruptcy proceeding by or against a bankrupt
Party under the U.S. Bankruptcy Code, the other Party shall be entitled to a
complete duplicate of (or complete access to, as appropriate) any intellectual
property and all embodiments of such intellectual property, and same, if not
already in the other Party's possession, shall be promptly delivered to the
other Party (a) upon any such commencement of a bankruptcy proceeding, upon the
other Party's written request therefor, unless the non-bankrupt Party (or a
trustee on behalf of the non-bankrupt Party) elects to continue to perform all
of its obligations under this License

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Agreement or (b) if not delivered under (a) above, upon the rejection of this
License Agreement by or on behalf of the non-bankrupt Party, upon written
request therefor by the other Party.

      12.6 EFFECTS OF TERMINATION. In addition to any other remedies which may
be available at law or equity upon termination of this License Agreement the
rights and obligations of the Parties shall be as set forth in this Section
12.6.

      (a) The following provisions shall remain in full force and effect after
the expiration or termination of this License Agreement: Section 6.5 (solely
with respect to any ongoing possession or exchange of the other Party's
Confidential Information); Section 6.7; Article 7 (only with respect to accrued
rights and obligations pursuant to Section 12.7); Article 9 (Confidentiality);
Section 10.3(c), 10.5 (Disclaimers); Article 11 (Indemnification); Article 12
(Term and Termination); and Article 14 (General).

      (b) The Parties shall retain their respective ownership rights as set
forth in Section 6.1(a). Amgen shall have the right, mutatis mutandis, to file,
prosecute, defend and maintain Joint Patent Rights under Section 6.2(b) (with
Hyseq having the right mutatis mutandis to comment with respect to the claims of
Joint Patent Rights not relating to products which may in any way affect the
rights conferred to Amgen to Develop, manufacture and Commercialize Licensed
Products) and Product Trademarks under Section 6.2(d), enforce Joint Patent
Rights under Section 6.3(b) (with Hyseq having the right mutatis mutandis to
assume any enforcement and/or defense action not taken by Amgen with respect to
the claims of Joint Patent Rights not relating to products which may in any way
affect the rights conferred to Amgen to Develop, manufacture and Commercialize
Licensed Products) and Product Trademarks under Section 6.3(c); and defend any
action claiming the infringement of any Third Party Patent Rights or any Third
Party Trademark under Section 6.4(a) and to publish under Article 8.

      (c) Hyseq shall within [***] (other than with respect to Amgen Material
and Manufacturing Information, in which case by no later than completion of its
obligations, if any, under Section 12.6(g) below) destroy, or at Amgen's request
return, all Amgen Confidential Information, Amgen Know-How and Amgen Material
and Manufacturing Information (other than with respect to maintaining one (1)
archival copy of Confidential Information related thereto for its legal files,
for the sole purpose of determining its obligations hereunder) and shall provide
Amgen with certification by an officer of Hyseq that all such materials have
been returned to Amgen.

      (d) Hyseq shall promptly transfer to Amgen ownership of all Regulatory
Filings and Regulatory Approvals then in its name for all Licensed Products and
shall notify the appropriate Regulatory Authorities and take any other action
reasonably necessary to effect such transfer of ownership. Hyseq shall assign to
Amgen Hyseq's right, title and interest in the Product Trademarks.

      (e) Amgen shall have the right to use Hyseq's Trademarks in the selling of
any existing inventory of Licensed Product(s) and to use Promotional Materials
it then has on hand, provided however, that Amgen promptly creates new
Promotional Materials (which do not use Hyseq's corporate name and/or logo),
with no obligation of accounting to Hyseq.

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      (f) Hyseq shall within [***] (other than with respect to Third Party
agreements entered into pursuant to Section 6.8, in which case by no later than
completion of its obligations if any under Section 12.6(g) below), at the
request of Amgen, assign (if assignable under its terms) to Amgen all of Hyseq's
rights and obligations under any then-existing Third Party licenses having a
license grant limited specifically to Licensed Products, regarding the making,
having made, use, selling, offering to sell, and importing, exporting or
otherwise transferring physical possession of or otherwise transferring title in
or to Licensed Products and shall not (until receiving notice of whether or not
Amgen desires such an assignment) terminate or amend any such Third Party
license. Otherwise, Hyseq shall, at the request of Amgen, sublicense (if
sublicensable under its terms) to Amgen all of Hyseq's rights and obligations
under any then-existing Third Party licenses regarding the making, having made,
use, selling, offering to sell, and importing, exporting or otherwise
transferring physical possession of or otherwise transferring title in or to
Licensed Products and shall not (until receiving notice of whether or not Amgen
desires such a sublicense) terminate or amend any such Third Party license. Such
assignment or sublicense shall be made for no additional consideration and be
under the same terms and conditions as the underlying agreement.

      (g) In the event Hyseq shall (i) have been using a Third Party contract
manufacturer(s) to manufacture Licensed Products, it shall only be obligated
with respect to the manufacture and supply of Licensed Products under this
License Agreement to assign its agreement with each such Third Party contract
manufacturer to Amgen or (ii) have been manufacturing Licensed Products at its
own facilities, it shall remain responsible for supplying the reasonable amounts
of Licensed Products for such reasonable period of time as to allow Amgen to
obtain an alternate source of supply, if necessary, while ensuring an
uninterrupted supply of Licensed Product of suitable quality and quantity
required for the Development and Commercialization to proceed. Once
manufacturing responsibility has been successfully transferred, Hyseq shall no
longer be responsible for the manufacture and supply of Licensed Products to
Amgen for the Development and Commercialization of Licensed Products in the
Territory and for making any decision with respect thereto and shall no longer
be responsible for any obligations pursuant to Article 4. In the event Hyseq is
obligated to continue to supply Licensed Products under this Section 12.6(g),
Amgen shall use [***] to identify one or more viable Third Party manufacturers
in order to transfer manufacturing operations as soon as commercially
reasonable.

      (h) Amgen hereby agrees to Indemnify the Hyseq Indemnitees from and
against any and all Losses resulting from any Third Party claims, suits, actions
or demands resulting directly or indirectly from the Development, manufacture or
Commercialization of Licensed Products (including a claim that a Licensed
Product caused death or personal injury of any kind). To be eligible to be
Indemnified as described above in this Section 12.6(h), the Hyseq Indemnitees
shall provide Amgen with prompt notice of any claim (with a description of the
claim and the nature and amount of any such Loss) giving rise to the
indemnification obligation pursuant to this Section 12.6(h) and the exclusive
ability to defend such claim (with the reasonable cooperation of Hyseq
Indemnitees); provided however, that Amgen shall be relieved of its obligations
only if any failure by the Hyseq Indemnitee to deliver prompt notice shall have
been prejudicial to its ability to defend such action. Hyseq shall have the
right to retain its own counsel, at its own expense, if representation of the
counsel of Amgen would be inappropriate

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due to actual or potential differing interests between the Parties. Neither
Party shall settle or consent to the entry of any judgment with respect to any
claim for Loss for which indemnification is sought[***]. Amgen's obligation to
Indemnify the Hyseq Indemnitees pursuant to this Section 12.6(h) shall not apply
to the extent of any Losses (i) that arise from the [***] of any Hyseq
Indemnitee (including but not limited to that arising from the Development of
Collaboration Product by Hyseq); (ii) that arise from Hyseq's breach of any
representation, warranty, covenant or obligation under this License Agreement;
or (iii) for which Hyseq is obligated to Indemnify the Amgen Indemnitees
pursuant to Section 11.2 of this License Agreement.

      (i) In the event that Amgen becomes entitled to terminate this License
Agreement at any time after the First Commercial Sale, the Parties will mutually
agree upon the text of a press release announcing the termination of this
License Agreement. After a notice of termination has been delivered pursuant to
any one of Sections 12.2 to 12.4, Hyseq shall, in no event in excess of [***]
after the delivery date of such notice (other than with respect to obligations
which explicitly exceed such [***] period), conduct an orderly transition of
rights and responsibilities from Hyseq to Amgen or to a Third Party, as the case
may be. Further, each Party shall cooperate and assist the other Party to effect
any such transition of rights and responsibilities in an orderly, reasonable and
businesslike manner. Such assistance shall include, but not be limited to (i)
making its personnel and other resources reasonably available to Amgen, as
necessary and (ii) transferring copies of all relevant information, files or
data containing Information and all Materials to Amgen.

      (j) Except as expressly set forth in this Section 12.6, all other rights
and obligations shall terminate.

      12.7 ACCRUED RIGHTS. Termination, relinquishment or expiration of any
licenses under this License Agreement or of this License Agreement for any
reason in accordance with this Article 12 shall be without prejudice to any
rights which shall have accrued to the benefit of either Party or any liability
incurred by either Party prior to the effective date of such termination,
relinquishment or expiration nor preclude either Party from pursuing all rights
and remedies it may have hereunder or at law or in equity with respect to any
breach of this License Agreement nor prejudice either Party's right to obtain
performance of any obligation.

                                   ARTICLE 13
                               DISPUTE RESOLUTION

      13.1 DISPUTES. The Parties recognize that disputes as to certain matters
may from time to time arise during the term of this License Agreement which
relate to either Party's rights and/or obligations hereunder. It is the
objective of the Parties to establish procedures to facilitate the resolution of
disputes arising from, concerning or in any way relating to this License
Agreement in an expedient manner by mutual cooperation and without resort to
litigation. To accomplish this objective, the Parties agree to follow the
procedures set forth in this Section 13.1 if and when a dispute arises under
this License Agreement. The Parties shall undertake good faith efforts to
resolve any such dispute in good faith. In the event the Parties shall be unable
to resolve such dispute, either Party may, by written notice to the other Party,
have any dispute

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between the Parties referred to [***]:

            [***]:            [***]

            [***]:            [***]

            [***]. Notwithstanding the above, either Party shall be entitled at
all times and without delay to seek equitable relief.

      13.2 GOVERNING LAW; JUDICIAL RESOLUTION. Resolution of all disputes
arising out of or related to this License Agreement, or the performance,
enforcement, breach or termination of this License Agreement and any remedies
relating thereto, shall be governed by and construed under the substantive laws
of the State of California as applied to agreements executed and performed
entirely in the State of California by residents of the State of California,
without regard to conflicts of law rules. Any dispute arising under this License
Agreement shall be submitted to a state or federal court of competent
jurisdiction in California; provided however, that if Amgen is the initiating
Party in a dispute, its shall bring such suit in a state or federal court which
has jurisdiction over Sunnyvale, California; and if Hyseq is the initiating
Party in a dispute, its shall bring such suit in a state or federal court which
has jurisdiction over Thousand Oaks, California.

      13.3 PATENT AND TRADEMARK DISPUTE RESOLUTION. Notwithstanding the above
Section 13.2, as between the Parties, any dispute, controversy or claim relating
to the scope, validity, enforceability or infringement of any Amgen Patent
Rights or Joint Patent Rights or of any Product Trademark shall be submitted to
a court of competent jurisdiction in the Territory in which such Patent Rights
or Trademark rights were granted or arose. Notwithstanding the foregoing, any
dispute, controversy or claim relating to the scope, validity, enforceability or
infringement of any United States patent application or patent within Amgen
Patent Rights or Joint Patent Rights shall be submitted to a court of competent
jurisdiction in the State of California.

                                   ARTICLE 14

                                     GENERAL

      14.1 FORCE MAJEURE. Both Parties shall be excused from the performance of
their obligations under this License Agreement to the extent that such
performance is prevented by Force Majeure and the nonperforming Party promptly
provides notice of the prevention to the other Party. Such excuse shall be
continued so long as the condition constituting Force Majeure continues and the
nonperforming Party uses reasonable efforts to remove the condition. When such
circumstances arise, the Parties shall discuss what, if any, modification of the
terms of this License Agreement may be required in order to arrive at an
equitable solution.

      14.2 NOTICES. Any notice required or permitted to be given under this
License Agreement shall be in writing, shall specifically refer to this License
Agreement and shall be deemed to have been sufficiently given for all purposes
if mailed by first class certified or

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registered mail, postage prepaid, express delivery service or personally
delivered or, if sent by facsimile, electronic transmission is confirmed. Unless
otherwise notified in writing, the mailing addresses and fax numbers for notice
of the Parties shall be as described below.

            For Hyseq:           Hyseq, Inc.
                                 670 Almanor Ave.
                                 Sunnyvale, CA 94085-1710
                                 Phone: (408) 524-8100
                                 Facsimile:(408) 524-8415
                                 Attn: General Counsel

                                 With a copy to: Chief Financial Officer

            For Amgen:           Amgen Inc.
                                 One Amgen Center Drive
                                 Thousand Oaks, CA 91320-1799

                                 Fax: (805) 499-6058
                                 Attention: Vice President, Licensing

                                 With a copy to: Corporate Secretary

      14.3 MAINTENANCE OF RECORDS. Each Party shall keep and maintain all
records required by law or regulation with respect to Licensed Products and
shall make copies of such records available to the other Party upon request.

      14.4 NO STRICT CONSTRUCTION. This License Agreement has been prepared
jointly and shall not be strictly construed against either Party.

      14.5 ASSIGNMENT. Other than as set forth in Sections 2.3 or 14.6, [***].
This License Agreement shall be binding on the successors and assigns of the
assigning Party, and the name of a Party appearing herein shall be deemed to
include the name(s) of such Party's successors and permitted assigns to the
extent necessary to carry out the intent of this License Agreement. Any
assignment or attempted assignment by either Party in violation of the terms of
this Section 14.5 shall be null and void and of no legal effect. The assigning
Party shall forward to the other Party a copy of those portions of each fully
executed assignment agreement which relate to the assumption of the rights and
responsibilities of the assigning Party, within [***] of the execution of such
assignment agreement.

      14.6 PERFORMANCE BY AFFILIATES. Each of Amgen and Hyseq acknowledge that
obligations under this License Agreement may be performed by Affiliates of Amgen
and Hyseq. Each of Amgen and Hyseq guarantee performance of this License
Agreement by its Affiliates, notwithstanding any assignment to Affiliates in
accordance with Section 14.5 of this License Agreement. Wherever in this License
Agreement the Parties delegate responsibility to Affiliates or local operating
entities, the Parties agree that such affiliates/entities may not make decisions
inconsistent with this License Agreement, nor amend the terms of this License
Agreement or act

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contrary to its terms in any way. Hyseq shall forward to Amgen a copy of each
fully executed license or sublicense agreement, within [***] of the execution of
each such license or sublicense agreement.

      14.7 COUNTERPARTS. This License Agreement may be executed in two (2) or
more counterparts, each of which shall be deemed an original but all of which
together shall constitute one and the same instrument.

      14.8 SEVERABILITY. If any one or more of the provisions of this License
Agreement are held to be invalid or unenforceable by any court of competent
jurisdiction from which no appeal can be or is taken, such provisions shall be
considered severed from this License Agreement and shall not serve to invalidate
any remaining provisions hereof. The Parties shall make a good faith effort to
replace any invalid or unenforceable provision with a valid and enforceable one
such that the objectives contemplated by the Parties when entering this License
Agreement, as evidenced by the terms of this License Agreement in accordance
with Section 14.16, may be realized.

      14.9 HEADINGS. The headings for each Article and Section in this License
Agreement have been inserted for convenience of reference only and are not
intended to limit or expand on the meaning of the language contained in the
particular Article or Section. Unless otherwise specified, (a) references in
this License Agreement to any Article, Section or Exhibit shall mean references
to such Article, Section or Exhibit of this License Agreement, (b) references in
any Section to any clause are references to such clause of such Section, and (c)
references to any agreement, instrument or other document in this License
Agreement refer to such agreement, instrument or other document as originally
executed or, if subsequently varied, replaced or supplemented from time-to-time,
as so varied, replaced or supplemented and in effect at the relevant time of
reference thereto.

      14.10 FURTHER ACTIONS. Each Party agrees to execute, acknowledge and
deliver such further instruments, and to do all such other acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
License Agreement.

      14.11 INDEPENDENT CONTRACTORS. The relationship between Hyseq and Amgen
created by this License Agreement is one of independent contractors. This
License Agreement does not create any agency, distributorship,
employee-employer, partnership, joint venture or similar business relationship
between the parties. Neither Party is a legal representative of the other Party,
and neither Party can assume or create any obligation, representation, warranty
or guarantee (express or implied) on behalf of the other Party for any purpose
whatsoever. Each Party shall use its own discretion and shall have complete and
authoritative control over its employees and the details of performing its
obligations under this License Agreement.

      14.12 NO BENEFIT OF THIRD PARTIES. The representations, warranties,
covenants and agreements set forth in this License Agreement are for the sole
benefit of the Parties hereto and their successors and permitted assigns, and
they shall not be construed as conferring any rights on any Third Parties.

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      14.13 USE OF NAME. Except as expressly provided in this License Agreement,
no Party hereto shall use, and no rights are granted in or to, the names or
Trademarks (including the names "Amgen" and "Hyseq"), physical likeness,
employee names or owner symbol of the other Party for any purpose (including,
without limitation, private or public securities placements) without the prior
written consent of the affected Party, such consent not to be unreasonably
withheld or delayed so long as such use of name is limited to an objective
statement of fact rather than for endorsement purposes. Neither Party shall use
any Trademark which either substantially resembles or is confusingly similar to,
misleading or deceptive with respect to, or which dilutes any of the other
Party's Trademarks in connection with the subject matter of this License
Agreement.

      14.14 NO WAIVER. Any delay in enforcing a Party's rights under this
License Agreement or any waiver as to a particular default or other matter shall
not constitute a waiver of such Party's rights to the future enforcement of its
rights under this License Agreement, except with respect to an express written
and signed waiver relating to a particular matter for a particular period of
time.

      14.15 EXPORT REQUIREMENTS. It is understood and acknowledged that the
transfer of certain commodities and technical data is subject to United States
laws and regulations controlling the export of such commodities and technical
data, including all Export Administration Regulations of the United States
Department of Commerce. Each Party hereby agrees and by entering into this
License Agreement gives written assurance that it shall comply with all United
States laws and regulations controlling the export of commodities and technical
data within Information and Materials, that it will be solely responsible for
any violation of any such laws and regulations by itself, its Affiliates or its
Sublicensees, and that it will indemnify, defend and hold the other Party
harmless from any liability in the event of any legal action of any nature
occasioned by such violation, pursuant to Section 11.1 (in the case of Amgen) or
Section 11.2 (in the case of Hyseq).

      14.16 ENTIRE AGREEMENT; AMENDMENT. This License Agreement (including all
Exhibits); that certain Warrant Purchase Agreement, dated January 8, 2002; and
any rights and obligations surviving, by its terms, termination of that certain
Collaboration Agreement (as defined herein on Page 1) set forth the complete,
final and exclusive agreement and all the covenants, promises, agreements,
warranties, representations, conditions and understandings between the Parties
hereto and supersedes and terminates all prior agreements and understandings
between the Parties. There are no covenants, promises, agreements, warranties,
representations, conditions or understandings (either oral or written) between
the Parties other than as are set forth herein and therein. This License
Agreement may only be modified or supplemented in a writing expressly stated for
such purpose and signed by an authorized officer of each Party (i.e., it may not
be modified by any purchase order, change order, acknowledgment, order
acceptance, standard terms of sale, invoice or the like).

      14.17 EXHIBITS. All Exhibits referenced herein and attached hereto are
incorporated in this License Agreement by reference.

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      IN WITNESS WHEREOF, the Parties have executed this License Agreement in
duplicate originals by their duly authorized representatives as of the Effective
Date.

<TABLE>
<S>                                          <C>
AMGEN INC.                                   HYSEQ, INC.
                                             (D.B.A. HYSEQ PHARMACEUTICALS)

By:                                          By:
   ---------------------------------            ---------------------------------

Print Name:                                  Print Name:
           -------------------------                    -------------------------

Title:                                       Title:
      ------------------------------               ------------------------------
</TABLE>

                                       31
<PAGE>

                                    EXHIBIT A

                                  DEFINED TERMS

      A.1 "AFFILIATE" shall mean, except as provided below, an individual, a
partnership, a joint venture, a corporation, a trust, an estate, an
unincorporated organization, a government or any department or agency thereof,
or any other entity or any combination of the aforementioned entities that,
directly or indirectly, through one or more intermediaries, controls, is
controlled by or is under common control with Amgen or Hyseq. For purposes of
this definition, "control" shall mean the possession, direct or indirect, of the
power to cause the direction of the management and policies of a Party, whether
through ownership of more than fifty percent (50%) of the voting securities of
such Party, by contract or otherwise.

      A.2 "ALFIMEPRASE" shall mean the polypeptide having the amino acid
sequence which is set forth in Exhibit B.

      A.3 "AMGEN KNOW-HOW" shall mean all Information and Material Controlled by
Amgen prior to or on the Effective Date necessary to Develop, manufacture or
Commercialize Licensed Products, including but not limited to the following
information: (1) information disclosed in the IND for Alfimeprase as of the
Effective Date; (2) information disclosed as of the Effective Date in any IND
supplements for Alfimeprase; (3) all Amgen-sponsored collaborator data and
results (subject to any contractual confidentiality obligations of Amgen to
Third Parties regarding such results); (4) any regulatory data which Amgen
provides to Hyseq; (5) sequence information of other Licensed Products and
information regarding their activity; and (6) such information which Amgen
expressly designates in writing it intends to include as Amgen Know-How under
this License Agreement; provided however, that Amgen Know-How shall exclude
Amgen Material and Manufacturing Information.

      A.4 "AMGEN MATERIAL AND MANUFACTURING INFORMATION" shall mean the most
current version of (i) the Materials (other than Licensed Products); and (ii)
the Information pertaining to the manufacture of Licensed Products including,
without limitation, Information contained in the CMC section of any applicable
Regulatory Filings or Information regarding Amgen's manufacturing facility; and
(iii) Information regarding the Materials.

      A.5 "AMGEN PATENT RIGHTS" shall mean Amgen's rights in (a) those Patent
Rights Controlled by Amgen on the Effective Date with respect to the Licensed
Products and listed in Exhibit C and (b) all Patent Rights Controlled by Amgen
prior to or during the term of the License Agreement that claim Amgen Know-How.

      A.6 "AMGEN TECHNOLOGY" shall mean all Amgen Patent Rights and Amgen
Know-How and Amgen's interest in the Joint Patent Rights and Joint Know-How.

      A.7 "ASIAN COUNTRIES" shall mean one or more of the following: [***].

      A.8 "CALENDAR QUARTER" shall mean the respective periods of three (3)
consecutive calendar months ending on either March 31, June 30, September 30, or
December 31 for so long as this License Agreement is in effect.

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-1
<PAGE>

      A.9 "CALENDAR YEAR" means each successive period of twelve (12) months
commencing on January 1 and ending on December 31.

      A.10 "COMMERCIALIZE" OR "COMMERCIALIZATION" shall mean all activities
relating to the manufacturing, promotion, and other pre-launch and post-launch
marketing and sale activities of Licensed Products and shall include without
limitation, Phase IV clinical trials (as defined in the Collaboration Agreement)
or equivalent clinical trials conducted following Regulatory Approval to market
such Licensed Product.

      A.11 "[***] EFFORTS" shall mean [***].

      A.12 "COMPETITIVE PRODUCT" shall mean [***].

      A.13 "CONFIDENTIAL INFORMATION" shall mean all Information received by
either Party from the other Party pursuant to this License Agreement, other than
that portion of such Information which:

            (a)   is publicly disclosed by the disclosing Party, either before
                  or after it becomes known to the receiving Party;

            (b)   was known to the receiving Party, without obligation to keep
                  it confidential, prior to when it was received from the
                  disclosing Party;

            (c)   is subsequently disclosed to the receiving Party by a Third
                  Party lawfully in possession thereof without obligation to
                  keep it confidential;

            (d)   has been publicly disclosed other than by the disclosing Party
                  and without breach of an obligation of confidentiality with
                  respect thereto; or

            (e)   has been independently developed by the receiving Party
                  without the aid, application or use of Confidential
                  Information, as demonstrated by competent written proof.

      A.14 "CONTROL" OR "CONTROLLED" shall mean possession of the ability to
grant a license or sublicense as provided for herein under such intellectual
property right without violating the terms of any agreement or other arrangement
with any Third Party.

      A.15 "DEVELOPMENT" OR "DEVELOP" shall mean all research, pre-clinical,
process development/manufacturing and clinical activities undertaken for a
Licensed Product required to successfully complete Pivotal Trials in the
Territory. For the avoidance of doubt, these activities shall include clinical
drug development activities, including among other things: test method
development and stability testing, toxicology, formulation, statistical analysis
and report writing, product approval and registration, and regulatory affairs
related to the foregoing. When used as a verb, "Develop" means to engage in
Development.

      A.16 "DOLLAR" shall mean a United States dollar, and "$" shall be
interpreted accordingly.

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-2
<PAGE>

      A.17 "DRUG APPROVAL APPLICATION" shall mean an application for Regulatory
Approval required before commercial sale or use of a Licensed Product as a drug
or to treat a particular indication in a regulatory jurisdiction, including
without limitation: (a) (i) a Biologics License Application (BLA) pursuant to 21
C.F.R. 601.2, submitted to the FDA, or any successor application or procedure
and (ii) any counterpart of a U.S. BLA in another country in the Territory; and
(b) all supplements and amendments, including supplemental BLAs (and any foreign
counterparts), that may be filed (e.g., to expand the label) with respect to the
foregoing.

      A.18 "FDA" shall mean the United States Food and Drug Administration, or
any successor thereto.

      A.19 "FIRST COMMERCIAL SALE" shall mean the initial transfer by Hyseq or
its Affiliates or Sublicensees under this License Agreement of a Licensed
Product to a non-Sublicensee Third Party in exchange for cash or some equivalent
to which value can be assigned for the purpose of determining Net Sales,
following Regulatory Approval to market such Licensed Product.

      A.20 "FORCE MAJEURE" shall mean any occurrence beyond the reasonable
control of a Party that prevents or substantially interferes with the
performance by such Party of any of its obligations hereunder, if such occurs by
reason of any act of God, flood, fire, explosion, earthquake, breakdown of
plant, shortage of critical equipment, loss or unavailability of manufacturing
facilities or material, strike, lockout, labor dispute, casualty or accident, or
war, revolution, civil commotion, acts of public enemies, blockage or embargo,
or any injunction, law, order, proclamation, regulation, ordinance, demand or
requirement of any government or of any subdivision, authority or representative
of any such government, inability to procure or use materials, labor, equipment,
transportation, or energy sufficient to meet manufacturing needs without the
necessity of allocation, or any other cause whatsoever, whether similar or
dissimilar to those above enumerated, beyond the reasonable control of such
Party, if and only if the Party affected shall have used reasonable efforts to
avoid such occurrence and to remedy it promptly if it shall have occurred.

      A.21 "GAAP" shall mean United States generally accepted accounting
principles.

      A.22 "IND" shall mean an Investigational New Drug application.

      A.23 "INFORMATION" shall mean all tangible and intangible techniques,
technology, practices, trade secrets, inventions (whether patentable or not),
methods, knowledge, know-how, conclusions, skill, experience, test data and
results (including pharmacological, toxicological and clinical test data and
results), analytical and quality control data, results or descriptions, software
and algorithms.

      A.24 "JOINT KNOW-HOW" shall mean Information and Materials characterized,
conceived, developed, derived, generated or identified jointly by employees of
or consultants to Hyseq and employees of or consultants to Amgen from the
Effective Date through the Term.

      A.25 "JOINT PATENT RIGHTS" shall mean all Patent Rights that claim or
disclose Joint Know-How.

                                      A-3
<PAGE>

      A.26 "LICENSED PRODUCT(s)" shall mean [***]

      A.27 "LOSSES" shall mean liabilities, costs, fees, expenses and/or losses,
including without limitation reasonable legal costs and expenses and attorneys'
fees for outside counsel.

      A.28 "MATERIALS" shall mean certain biological materials including, but
not limited to, Licensed Products, screens, animal models, cell lines, cells,
nucleic acids, receptors and reagents.

      A.29 "NET SALES" shall mean all revenues recognized in accordance with
GAAP from the sale or other disposition of Licensed Products by Hyseq or its
Affiliates or Sublicensees to a non-Sublicensee Third Party after deducting
[***]

      A.30 "PATENT RIGHTS" shall mean (i) a pending application for a patent,
including without limitation any provisional, converted provisional, continued
prosecution application, continuation, divisional or continuation-in-part
thereof; or (ii) an issued, unexpired patent (with the term "patent" being
deemed to encompass, without limitation, an inventor's certificate) which has
not been held invalid or unenforceable by a court of competent jurisdiction from
which no appeal can be taken or has been taken within the required time period,
including without limitation any substitution, extension, registration,
confirmation, reissue, re-examination, renewal or any like filing thereof.

      A.31 "PIVOTAL TRIAL(s)" shall mean those clinical trials on sufficient
numbers of patients that, if the defined end-points are met, are designed (and
agreed to by the FDA, or other Regulatory Authorities in the Territory based
upon existing data in the same patient population) as of the start of the trial
to definitively establish that a drug is safe and efficacious for its intended
use, and to define warnings, precautions and adverse reactions that are
associated with the drug in the dosage range to be prescribed, and provide
pivotal data supporting Regulatory Approval of such drug or label expansion of
such drug and that satisfy the requirements of 21 CFR 321.21(c) (or its
successor regulation), or an equivalent foreign clinical trial.

      A.32 "PRODUCT TRADEMARK" shall mean any trademarks and trade names (and
trademark applications (whether or not registered) together with all goodwill
associated therewith, and any renewals, extensions or modifications thereto in
the Territory), trade dress and packaging which (a) are owned by or Controlled
by either Party and (b) are applied to or used with Licensed Products or any
Promotional Materials.

      A.33 "PROMOTIONAL MATERIALS" shall mean all sales representative training
materials and all written, printed, graphic, electronic, audio or video matter
including, but not limited to, journal advertisements, sales visual aids, direct
mail, direct-to-consumer advertising, Internet postings, broadcast
advertisements, and sales reminder aids (e.g., scratch pads, pens and other such
items) intended for use or used by a Party in connection with any Promotion (as
defined herein) or Detailing (as defined in the Collaboration Agreement) of a
Licensed Product, except for (i) the Regulatory Authority-approved full
prescribing information for a Licensed Product, including any required patient
information and (ii) all labels and other written, printed or graphic matter
upon any container, wrapper, or any package insert or outsert utilized with or
for a Licensed Product.

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-4
<PAGE>

      A.34 "REGULATORY APPROVAL" shall mean any approvals (including
supplements, amendments, pre- and post-approvals and price approvals), licenses,
registrations or authorizations (including designations of a Licensed Product as
an "Orphan Product" under the Orphan Drug Act) of any national, supra-national,
regional, state or local regulatory agency, department, bureau, commission,
council or other governmental entity, including the FDA or equivalent foreign
Regulatory Authorities, necessary for the distribution, use or sale of a
Licensed Product in a regulatory jurisdiction. Regulatory Approval shall not
include any site license for an Amgen manufacturing facility.

      A.35 "REGULATORY AUTHORITY" shall mean the FDA or any counterpart of the
FDA outside the United States.

      A.36 "REGULATORY FILINGS" shall mean collectively, INDs, BLAs,
establishment license applications (ELAs) and drug master files (DMFs),
applications for designation of a Licensed Product as an "Orphan Product" under
the Orphan Drug Act, or any other similar filings (including any foreign
equivalents and further including any related correspondence and discussions),
and all data contained therein, as may be required by the FDA or equivalent
foreign Regulatory Authorities for the Development, manufacture or
Commercialization of a Licensed Product.

      A.37 "ROYALTY" OR "ROYALTIES" shall mean those amounts payable as
royalties by Hyseq to Amgen pursuant to Section 5.2 of this License Agreement.

      A.38 "SUBLICENSEE" shall mean a Third Party to whom Hyseq shall have
granted a license or sublicense under Hyseq's rights pursuant to Section 2.3 to
make, have made, use, sell, offer for sale, or import a Licensed Product in one
or more countries in the Territory. Solely for the purpose of any compensation
payable to Amgen hereunder, "Sublicensee" shall include a Third Party to whom
Hyseq or another Sublicensee shall have granted the right to distribute one or
more Licensed Product(s), wherein such distributor pays to Hyseq or such another
Sublicensee a royalty based upon the revenues received by the distributor for
the sale of such Licensed Product(s), but shall not include (i) any Third Party
who receives an implied license to use a unit of Licensed Product(s), arising by
operation of law, as a consequence of the purchase of said unit of Licensed
Product(s); or (ii) any Third Party where Hyseq or such another Sublicensee
merely sells such Licensed Product(s) at a fixed transfer price to such
distributor for resale by such distributor and Hyseq is not compensated based on
the resale price of such Licensed Product by such distributor.

      A.39 "TERM" shall have the meaning set forth in Section 12.1.

      A.40 "TERRITORY" shall mean [***].

      A.41 "THIRD PARTY" shall mean any individual, a partnership, a joint
venture, a corporation, a trust, an estate, an unincorporated organization, a
government or any department or agency thereof, or any other than Amgen or Hyseq
or an Affiliate of either of them.

      A.42 "THIRD PARTY PAYMENT" shall mean all upfront payments, milestone
payments, license fees, royalties or other payments, payable to any Third Party
under any Third Party

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-5
<PAGE>

license agreement deemed necessary or useful to make, have made, use, sell,
offer to sell, and import, export or otherwise transfer physical possession of
or otherwise transfer title in a Licensed Product.

      A.43 "TRADEMARK" shall mean any and all corporate names, trade names,
service marks, logos or trademarks and trademark applications (whether or not
registered) together with all good will associated therewith, and any renewals,
extensions or modifications thereto either filed or used.

      A.44 "VALID CLAIM" shall mean (i) an unexpired claim of an issued patent
within the Amgen Patent Rights and Joint Patent Rights that has not been found
to be unpatentable, invalid or unenforceable by a court or other authority in
the country of the patent, from which decision no appeal is taken or can be
taken; or (ii) a claim of a pending application within the Amgen Patent Rights
and Joint Patent Rights, wherein such pending application claims a first
priority no more than [***] prior to the date upon which pendency is determined.

[***] INDICATES THAT CERTAIN INFORMATION ON THIS PAGE HAS BEEN OMITTED AND FILED
      SEPARATELY WITH THE COMMISSION PURSUANT TO RULE 24B-2. CONFIDENTIAL
      TREATMENT HAS BEEN REQUESTED WITH RESPECT TO THE OMITTED PORTIONS.

                                      A-6
<PAGE>

                                    EXHIBIT B

                         PROTEIN SEQUENCE OF ALFIMEPRASE

RN   259074-76-5  ZREGISTRY
CN   3-203-Fibrolase [3-serine] (Agkistrodon contortrix contortrix recombinant)
     (9CI)  (CA INDEX NAME)
FS   PROTEIN SEQUENCE
SQL  201
NTE

<TABLE>
<CAPTION>
----------------------------------------------------------------------
 type            ------ location ------         description
----------------------------------------------------------------------
<S>              <C>                       <C>
bridge           Cys-116     - Cys-196     disulfide bridge
bridge           Cys-156     - Cys-180     disulfide bridge
bridge           Cys-158     - Cys-163     disulfide bridge
----------------------------------------------------------------------
</TABLE>

SEQ      1 SFPQRYVQLV IVADHRMNTK YNGDSDKIRQ WVHQIVNTIN EIYRPLNIQF
        51 TLVGLEIWSN QDLITVTSVS HDTLASFGNW RETDLLRRQR HDNAQLLTAI
       101 DFDGDTVGLA YVGGMCQLKH STGVIQDHSA INLLVALTMA HELGHNLGMN
       151 HDGNQCHCGA NSCVMAAMLS DQPSKLFSDC SKKDYQTFLT VNNPQCILNK
       201 P

SEQ3     1 Ser-Phe-Pro-Gln-Arg-Tyr-Val-Gln-Leu-Val-
        11 Ile-Val-Ala-Asp-His-Arg-Met-Asn-Thr-Lys-
        21 Tyr-Asn-Gly-Asp-Ser-Asp-Lys-Ile-Arg-Gln-
        31 Trp-Val-His-Gln-Ile-Val-Asn-Thr-Ile-Asn-
        41 Glu-Ile-Tyr-Arg-Pro-Leu-Asn-Ile-Gln-Phe-
        51 Thr-Leu-Val-Gly-Leu-Glu-Ile-Trp-Ser-Asn-
        61 Gln-Asp-Leu-Ile-Thr-Val-Thr-Ser-Val-Ser-
        71 His-Asp-Thr-Leu-Ala-Ser-Phe-Gly-Asn-Trp-
        81 Arg-Glu-Thr-Asp-Leu-Leu-Arg-Arg-Gln-Arg-
        91 His-Asp-Asn-Ala-Gln-Leu-Leu-Thr-Ala-Ile-
       101 Asp-Phe-Asp-Gly-Asp-Thr-Val-Gly-Leu-Ala-
       111 Tyr-Val-Gly-Gly-Met-Cys-Gln-Leu-Lys-His-
       121 Ser-Thr-Gly-Val-Ile-Gln-Asp-His-Ser-Ala-
       131 Ile-Asn-Leu-Leu-Val-Ala-Leu-Thr-Met-Ala-
       141 His-Glu-Leu-Gly-His-Asn-Leu-Gly-Met-Asn-
       151 His-Asp-Gly-Asn-Gln-Cys-His-Cys-Gly-Ala-
       161 Asn-Ser-Cys-Val-Met-Ala-Ala-Met-Leu-Ser-
       171 Asp-Gln-Pro-Ser-Lys-Leu-Phe-Ser-Asp-Cys-
       181 Ser-Lys-Lys-Asp-Tyr-Gln-Thr-Phe-Leu-Thr-
       191 Val-Asn-Asn-Pro-Gln-Cys-Ile-Leu-Asn-Lys-
       201 Pro

                                       B-1
<PAGE>

                                    EXHIBIT C

                  AMGEN PATENT RIGHTS AS OF THE EFFECTIVE DATE

                                       C-1

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