EXECUTION COPY

              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.

       AGREEMENT TO TERMINATE THE INTEREST OF JAPAN TOBACCO INC. IN THE
                 MASTER RESEARCH LICENSE AND OPTION AGREEMENT

         THIS AGREEMENT TO TERMINATE THE INTEREST OF JAPAN TOBACCO INC. IN THE
MASTER RESEARCH LICENSE AND OPTION AGREEMENT (this "Agreement"), effective
December 31, 1999, (the "Effective Date") is made by and among ABGENIX, INC., a
Delaware corporation ("ABX") and JAPAN TOBACCO INC., a Japanese corporation
("JTI"), and XENOTECH, L.P., a California limited partnership ("XT") with
reference to the following facts and circumstances.

                                   RECITALS

         A. WHEREAS, Cell Genesys, Inc. ("CGI"), the predecessor company of ABX,
and JT Immunotech USA Inc. ("Immunotech"), a wholly-owned indirect subsidiary of
JTI, formed XT in 1991 to develop genetically modified strains of mice which can
produce fully human monoclonal antibodies, and to commercialize products
generated therefrom;

         B. WHEREAS, CGI assigned to ABX (its wholly-owned subsidiary at such
time) its interest in XT, and Immunotech merged into JT America Inc. ("JTA"), a
wholly-owned subsidiary of JTI, and its interest in XT was assigned to JTA by
operation of law;

         C. WHEREAS, JTA has agreed to sell to ABX, and ABX has agreed to
purchase, JTA's interest in XT pursuant to a Limited Partnership Interest and
Stock Purchase Agreement of even date herewith, by and between ABX and JTA (the
"Purchase Agreement");

         D. WHEREAS, XT, JTI and CGI were parties to a Master Research License
and Option Agreement dated effective as of June 28, 1996, as amended (the
"MRLOA"), to govern the parties' rights with respect to the development and
commercialization of Products;

         E. WHEREAS, JTI is willing to terminate its rights under and interest
in the MRLOA in exchange for certain consideration to be paid by ABX hereunder;

         NOW THEREFORE, for and in consideration of the covenants, conditions,
and undertakings hereinafter set forth, the Parties agree as follows:

1.       DEFINITIONS

         For purposes of this Agreement, capitalized terms set forth in this
Agreement and not otherwise defined herein shall have the meaning set forth in
the MRLOA.

         1.1 "ANTIGEN" shall mean a [*] that (a) is defined by a [*] thereof,
including any [*] thereto and (b) is identified by a [*] (as disclosed in an
[*] sufficient to [*]

[*] 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.

                                       1.



         1.2 "ANTIGEN INVENTION" shall mean any inventions that relate to (a)
the [*] of [*] that [*] to an [*] or [*] or such [*] or [*] of such [*] such
[*] and [*] that [*] such [*] (b) [*] such [*] or [*] other than those
described in (a); and (c) [*] described in (a) and/or (b); in each case that
are made, conceived or reduced to practice by or on behalf of [*] under the
MRLOA, together with all patent applications, patents and/or know-how
relating to, covering or claiming the foregoing.

         1.3 "CONTROLLED" shall mean the ability to grant licenses or
sublicenses with respect to a technology or material as provided in this
Agreement without breaching any agreement or other arrangement with a Third
Party.

         1.4 "MAJORITY-OWNED AFFILIATE OF JTI" shall mean an entity of which
JTI owns, directly or indirectly, more than [*] of the shares of such entity
entitled to vote in the election of directors or corresponding managing
authority.

         1.5 "PRODUCT ANTIGEN" shall have the meaning ascribed in the applicable
Product License executed pursuant to the MRLOA.

         1.6 "RESEARCH PROGRAM MATERIALS AND INFORMATION" shall mean: (i) [*]
(ii) [*] that [*] that [*] (iii) [*] that [*] or [*] that [*] (iv) [*]
that [*] that [*] or [*] and (v) information (and all [*] thereof) regarding
the [*] described in clauses (i) through (iv); in each case that are made,
conceived, reduced to practice or otherwise derived from the activities
conducted by the Parties pursuant to and in accordance with the MRLOA or any
Product License entered into pursuant to the MRLOA.

         1.7 "XENOMOUSE ANIMALS" shall mean transgenic mice which are Controlled
by ABX and which contain unrearranged human immunoglobulin genes that are
capable of producing human antibodies when immunized with an antigen.

2.       CONSIDERATION

         In consideration for JTI's agreement to relinquish its Buy-In Right
with respect to certain Selected Antigens under the MRLOA, ABX shall pay to
JTI Ten Million Dollars (US$10,000,000) on December 31, 1999. The payment
required to be made pursuant to this Section 2 shall be without [*] if any,
the [*]

[*] 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.

                                       2.



3. TERMINATION OF JTI'S RIGHTS UNDER THE MRLOA.

         3.1 JTI's rights under and interest in the MRLOA are hereby terminated
effective as of the Effective Date, including without limitation (a) its rights
under Section 3.1 thereof, (b) its rights to select certain Antigens for
development of antibody products binding thereto, and (c) its rights to maintain
and use a colony of XenoMouse Animals as provided in the MRLOA. JTI's
obligations under Articles 12 (excluding Section 12.2(a)) and 14 of the MRLOA
shall survive termination of JTI's interest in the MRLOA pursuant to this
Agreement solely with respect to activities conducted by JTI pursuant to the
MRLOA prior to the Effective Date. The termination of JTI's rights under and
interest in the MRLOA shall not affect JTI's rights under any Product License
entered into between JTI and XT prior to the Effective Date, or the rights of
ABX and XT under the MRLOA, which shall survive termination of JTI's interest in
the MRLOA.

         3.2 ABX and XT hereby release and discharge JTI from, and hereby waive
and relinquish, all disputes, claims, controversies, demands, rights,
obligations, liabilities, actions and causes of action of every kind and nature
arising out of activities conducted by ABX and XT pursuant to the MRLOA after
the Effective Date. The Parties intend that the MRLOA shall continue in full
force and effect as between ABX and XT, and that JTI's rights under the MRLOA
shall revert to XT.

4.       LICENSE GRANT.

         4.1 LICENSE UNDER ANTIGEN INVENTIONS. Subject to the terms and
conditions of this Agreement, JTI hereby grants to ABX a non-exclusive, fully
paid-up, royalty-free, perpetual, worldwide, sublicensable license to use
Antigen Inventions, except that such license shall not include a license to
use the Antigen Inventions relating to the [*] during the period in which the
relevant Product License for each such Product Antigen is in effect. In no
event shall JTI be obligated to disclose or provide to ABX any Research
Program Materials and Information relating to any Antigen Invention,
notwithstanding the foregoing license.

         4.2 NON-EXCLUSIVE LICENSE WITH RESPECT TO XENOMOUSE ANIMALS. Subject to
the terms and conditions of this Agreement, JTI hereby grants to ABX a
non-exclusive, fully paid-up, royalty-free, perpetual, sublicensable, worldwide
license under all intellectual property rights Controlled by JTI as of the
Effective Date that cover the creation, development, use, manufacture,
importation, offer for sale and sale of XenoMouse Animals.

         4.3 NON-EXCLUSIVE LICENSE UNDER PRODUCT ANTIGEN INVENTIONS ARISING
UNDER THE MRLOA. JTI hereby grants to ABX a non-exclusive, fully paid-up,
royalty-free, perpetual, sublicenseable, worldwide license under all
intellectual property rights Controlled by JTI covering Antigen Inventions
arising out of JTI's activities under the MRLOA with respect to any Product
Antigen (as defined in the MRLOA) for which either (a) JTI's option under the
MRLOA expires or terminates prior to JTI and XT entering into a Product License
therefor, or (b) JTI and XT have entered into a Product License, and such
Product License has terminated or expired (but not while such Product License is
in effect). In no event shall JTI be obligated to disclose or

[*] 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.

                                       3.



provide to ABX any Research Program Materials and Information relating to any
such Product Antigen or related Antigen Invention, notwithstanding the
foregoing license.

         4.4 NON-EXCLUSIVE LICENSE RELATING TO PROJECT TECHNOLOGY AND JT
INDEPENDENT INVENTIONS. JTI hereby grants to ABX a non-exclusive (even as to
JTI), worldwide, royalty-free, perpetual, sublicensable license under all
intellectual property rights in and to any inventions made by JTI in the course
of practicing any Project Technology, and all intellectual property rights in
and to any JT Independent Technology Controlled by JTI for all uses within the
Field or the Expanded Field. In no event shall JTI be obligated to disclose or
provide to ABX any materials created by JTI using the Project Technology or that
are within the JT Independent Technology, including without limitation any
transgenic animals, notwithstanding the foregoing license. The capitalized terms
in this Section 4.4 not defined in this Agreement shall have the meanings given
to them in the Amended and Restated Field License between ABX, JTA and XT of
even date herewith or the Amended Expanded Field License between ABX and JTA of
even date herewith.

         4.5 SUBLICENSE UNDER THE [*] JTI hereby grants to XT a
non-exclusive, worldwide, royalty-free, perpetual license under the [*] Such
license shall be sublicensable solely with respect to use of [*] JTI
covenants that it shall use all commercially reasonable efforts to maintain
in effect the [*] and that it shall promptly notify ABX of any material
communication or notice it delivers or receives that may adversely affect the
scope or effectiveness of ABX's license under this Section 4.5.

5.       PATENT ASSISTANCE.

         5.1 PATENT ASSISTANCE. JTI shall provide to ABX, during the four (4)
months following the Effective Date (the "Transition Period"), reasonable
assistance in connection with ABX's assumption of responsibility for the
prosecution of the Patent Rights (as defined in the Collaboration Agreement
between CGI (which assigned its interest therein to ABX), XT and JTA dated
June 12, 1991, as amended and as terminated as of the Effective Date) in
Japan. JTI and ABX shall conduct one face to face meeting in Japan for such
purpose during the Transition Period, with each Party bearing all costs for
its representatives' attendance at such meeting. Following the Transition
Period, JTI shall reasonably assist ABX in the prosecution and defense of the
Patent Rights in Japan upon ABX's written request, in which event ABX shall
reimburse JTI for its reasonable costs and expenses incurred in connection
therewith, including [*] at a [*] in advance by the Parties.

6.       INDEMNIFICATION

         6.1 BY JTI. Subject to ABX's compliance with Section 6.3, JTI agrees to
indemnify, defend and hold ABX and its Affiliates and their respective
directors, officers, employees and agents harmless from and against any losses,
claims, damages, liabilities, penalties and interest, or actions resulting
directly from any Third Party claims (collectively, "Liabilities") arising from

[*] 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.

                                       4.



any negligence or willful misconduct of JTI (or its directors, officers,
employees or agents) or the breach of any representations, warranties, covenants
or other obligations of JTI under this Agreement, except to the extent that such
Liabilities arise from ABX's breach of any of its representations, warranties,
covenants or other obligations under this Agreement or relate to any Liabilities
incurred in connection with any failure by ABX to pay any withholding taxes due
to a government authority in connection with ABX's performance of its
obligations and exercise of its rights under this Agreement, whether such taxes
are paid by ABX at the time of payment to JTI or imposed upon ABX by the
relevant authority at a later date.

         6.2 BY ABX. Subject to JTI's compliance with Section 6.3, ABX agrees to
indemnify, defend and hold JTI and its Affiliates and their directors, officers,
employees and agents harmless from and against any Liabilities arising from (i)
any negligence or willful misconduct of ABX (or its directors, officers,
employees, or agents); (ii) the breach of any representations, warranties,
covenants or other obligations of ABX under this Agreement, (iii) ABX's or its
Affiliates' activities under the MRLOA after the Effective Date, and (iv) any
failure by ABX to pay any withholding taxes due to a government authority in
connection with ABX's performance of its obligations and exercise of its rights
under this Agreement (whether such taxes are paid by ABX at the time of payment
to JTI or imposed upon ABX by the relevant authority at a later date), except in
each case to the extent that such Liabilities arise from JTI's negligence or
willful misconduct or breach of any of its representations, warranties,
covenants or other obligations under this Agreement.

         6.3 INDEMNIFICATION PROCEDURES. If a Party (the "Indemnitee") intends
to claim indemnification under this Article 6, it shall promptly notify the
indemnifying Party (the "Indemnitor") in writing of any Liability in respect of
which the Indemnitee or its directors, officers, employees or agents intend to
claim such indemnification, and the Indemnitor shall have the right to
participate in, and, to the extent the Indemnitor so desires, to assume the
defense thereof with counsel mutually satisfactory to the Parties. The indemnity
obligation of this Article 6 shall not apply to amounts paid in settlement of
any loss, claim, damage, liability or action if such settlement is effected
without the consent of the Indemnitor, which consent shall not be withheld or
delayed unreasonably. The failure to deliver written notice to the Indemnitor
within a reasonable time after the commencement of any such action shall not
relieve such Indemnitor of any liability to the Indemnitee under this Article 6,
except to the extent that such failure is prejudicial to its ability to defend
such action. The Party claiming indemnification under this Article 6 and its
directors, officers, employees and agents, shall cooperate fully with the
Indemnitor and its legal representatives in the investigation of any action,
claim or liability covered by this Article 6.

[*] 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.

                                       5.



7.       REPRESENTATIONS, WARRANTIES AND COVENANTS

         7.1 REPRESENTATIONS, WARRANTIES AND COVENANTS OF ABX. ABX represents
and warrants to JTI that (i) it has the full right and authority to enter into
this Agreement; (ii) it has taken all necessary action on its part to authorize
the execution and delivery of this Agreement and the performance of its
obligations hereunder; (iii) to the knowledge of ABX as of the Effective Date,
there are no existing or threatened actions, suits or claims pending with
respect to the subject matter hereof or the right of ABX to enter into and
perform its obligations under this Agreement; and (iv) it has not entered and
during the term of this Agreement will not enter any other agreement
inconsistent or in conflict with this Agreement.

         7.2 REPRESENTATIONS, WARRANTIES AND COVENANTS OF JTI. JTI represents
and warrants to ABX that (i) it has the full right and authority to enter into
this Agreement; (ii) it has taken all necessary action on its part to authorize
the execution and delivery of this Agreement and the performance of its
obligations hereunder; (iii) to the knowledge of JTI as of the Effective Date,
there are no existing or threatened actions, suits or claims pending with
respect to the subject matter hereof or the right of JTI to enter into and
perform its obligations under this Agreement; and (iv) it has not entered and
during the term of this Agreement will not enter any other agreement
inconsistent or in conflict with this Agreement.

8.       TERM; TERMINATION

         8.1 TERM. This Agreement shall commence on the Effective Date and,
unless earlier terminated as provided in this Article 8, shall continue in
effect for a period of twenty (20) years from the Effective Date.

         8.2 TERMINATION FOR BREACH. Either Party may terminate this Agreement
in the event the other Party shall have materially breached or defaulted in the
performance of any of its material obligations hereunder, and such breach or
default shall have continued for sixty (60) days after written notice thereof
was provided to the breaching Party by the nonbreaching Party that terminates
the Agreement as to the breaching Party. Any termination shall become effective
at the end of such sixty (60) day period unless the breaching Party has cured
any such breach or default prior to the expiration of the sixty (60) day period.
However, if the Party alleged to be in breach of this Agreement disputes such
breach within such sixty (60) day period, the other Party shall not have the
right to terminate this Agreement unless it has been determined by an
arbitration proceeding in accordance with Section 9.13 below that the allegedly
breaching Party did in fact materially breach this Agreement, and the breaching
Party fails to cure such breach within thirty (30) days following the final
decision of the arbitrators or such other time as directed by the arbitrators.

         8.3      EFFECT OF EXPIRATION OR TERMINATION.

                  8.3.1 ACCRUED OBLIGATIONS AND RIGHTS. Expiration or any
termination of this Agreement for any reason shall not relieve either Party of
any obligation accruing prior to such expiration or termination or release
either Party from any liability which at the time of such expiration or
termination has already accrued to such Party. Such termination or expiration
shall

[*] 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.

                                       6.



not preclude either Party from pursuing any rights and remedies it may have
hereunder or at law or in equity which accrued to it prior to such expiration
or termination.

                  8.3.2 SURVIVAL.  Articles 4, 5, 6, 7 and 9 and Section 8.3.2
shall  survive the  expiration or termination of this Agreement.

9.       MISCELLANEOUS PROVISIONS

         9.1 GOVERNING LAWS. This Agreement shall be interpreted and construed
in accordance with the laws of the State of California, USA, without regard to
conflict of laws principles.

         9.2 WAIVER. It is agreed that no waiver by a Party hereto of any breach
or default of any of the covenants or agreements herein set forth shall be
deemed a waiver as to any subsequent and/or similar breach or default.

         9.3 ASSIGNMENTS. Neither this Agreement nor any right or obligation
hereunder may be assigned or delegated, in whole or part, by either Party
without the prior written consent of the other; provided that such written
consent shall not be required where: (a) either Party assigns this Agreement to
any entity that acquires substantially all of the assets to which this Agreement
relates; (b) JTI assigns this Agreement to a Majority-Owned Affiliate of JTI; or
(c) ABX assigns this Agreement to an Affiliate. The terms and conditions of this
Agreement shall be binding on and inure to the benefit of the permitted
successors and assigns of the Parties. Notwithstanding the foregoing, ABX shall
not be obligated without its written consent to transfer XenoMouse Animals to
any Third Party or Affiliate of JTI, including without limitation any
successor-in-interest of JTI. Any assignment not in conformance with this
Section 9.3 shall be null, void and of no legal effect.

         9.4 INDEPENDENT CONTRACTORS. The relationship of the Parties is that of
independent contractors. The Parties shall not be deemed to be agents, partners
or joint venturers of the others for any purpose as a result of this Agreement
or the transactions contemplated thereby.

         9.5 COMPLIANCE WITH LAWS. In exercising their rights under this
Agreement, the Parties shall fully comply with the requirements of any and all
applicable laws, regulations, rules and orders of any governmental body having
jurisdiction over the exercise of rights under this Agreement.

         9.6 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
Agreement.

         9.7 NO IMPLIED OBLIGATIONS. Except as expressly provided herein,
nothing in this Agreement shall be deemed to require JTI to exploit the Licensed
Technology or to prevent JTI from commercializing products similar to or in
competition with any Product, in addition to or in lieu of such Products.

[*] 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.

                                       7.



         9.8 NOTICES. Any notice, request, approval or consent required or
permitted to be given between the Parties hereto shall be given in writing, and
shall be deemed to have been properly given if delivered in person, transmitted
by telecopy (with machine confirmation of transmission and confirmation by
personal delivery, first class certified mail or courier), or mailed by first
class certified mail to the other Party at the appropriate address set forth
below, or to such other address as may be designated in writing by a Party from
time to time in accordance with this Agreement.

         Japan Tobacco Inc.:                Japan Tobacco Inc.
                                            JT Building
                                            2-1 Toranoman 2-chome
                                            Minato-Ku, Tokyo 105
                                            Japan
                                            Fax:  011-81-3-5-479-0321
                                            Attn:  Vice President
                                            Pharmaceutical Division

         With a copy to:                    Gilbert, Segall and Young LLP
                                            430 Park Avenue
                                            New York, NY  10022
                                            Fax:  (212) 644-4051
                                            Attn:  Neal N. Beaton, Esq.

                                            Akros Pharma Inc.
                                            1400 Fashion Island Blvd.
                                            San Mateo, CA 94404
                                            Fax: (650) 312-8028
                                            Attn: President

         Abgenix, Inc. and                  Abgenix, Inc.
         Xenotech L.P.:                     7601 Dumbarton Circle
                                            Fremont, California 94555
                                            Fax: (510) 608-6511
                                            Attn: President


         With a copy to:                    Cooley Godward LLP
                                            3000 El Camino Real
                                            Five Palo Alto Square
                                            Palo Alto, CA 94306-2155
                                            Fax:  (650) 857-0663
                                            Attn:  Robert L. Jones, Esq.

         9.9 EXPORT LAWS. Notwithstanding anything to the contrary contained
herein, all obligations of the United States and Japan, of ABX and JTI are
subject to prior compliance with the export regulations and such other United
States or Japanese laws and regulations as may be

[*] 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.

                                       8.



applicable, and to obtaining all necessary approvals required by the
applicable agencies of the governments of the United States and Japan. JTI
shall be responsible for obtaining such approvals, and shall use efforts
consistent with prudent business judgment to obtain such approvals.

         9.10 SEVERABILITY. In the event that any provision of this Agreement
becomes or is declared by a court of competent jurisdiction to be illegal,
unenforceable or void, this Agreement shall continue in full force and effect
without said provision and the parties shall discuss in good faith appropriate
revised arrangements.

         9.11 FORCE MAJEURE. Nonperformance of any Party shall be excused to the
extent that performance is rendered impossible by strike, fire, earthquake,
flood, governmental acts or orders or restrictions, failure of suppliers, or any
other reason where failure to perform is beyond the reasonable control, and not
caused by the negligence, intentional conduct or misconduct of the
non-performing Party.

         9.12 NO CONSEQUENTIAL DAMAGES. IN NO EVENT SHALL ANY PARTY HERETO BE
LIABLE FOR SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THIS
AGREEMENT OR THE EXERCISE OF ITS RIGHTS HEREUNDER.

         9.13 DISPUTE RESOLUTION; ARBITRATION. The Parties will attempt to
resolve any dispute under this Agreement by mutual agreement, and, if required,
there shall be a face-to-face meeting between the Chief Executive Officer of ABX
and the Vice President of the Pharmaceutical Division of JTI. Any dispute under
this Agreement which is not settled after such meeting shall be finally settled
by binding arbitration, conducted in accordance with the Commercial Arbitration
Rules of the American Arbitration Association by three (3) arbitrators appointed
in accordance with said rules. The arbitration proceedings and all pleadings and
written evidence shall be in the English language. Any written evidence
originally in a language other than English shall be submitted in English
translation accompanied by the original or a true copy thereof. The costs of the
arbitration, including administrative and arbitrators' fees, shall be shared
equally by the parties to the arbitration. Each Party shall bear its own costs
and attorneys' and witness' fees; PROVIDED THAT the prevailing party in any
arbitration, as determined by the arbitration panel, shall be entitled to an
award against the other party in the amount of the prevailing party's costs and
reasonable attorneys' fees. A disputed performance or suspended performances
pending the resolution of the arbitration must be completed within thirty (30)
days following the final decision of the arbitrators. Any arbitration subject to
this Section 9.13 shall be completed within six (6) months from the filing of
notice of a request for such arbitration.

         9.14 COMPLETE AGREEMENT. It is understood and agreed between ABX and
JTI that this Agreement constitutes the entire agreement, both written and oral,
between the Parties with respect to the subject matter hereof, and supersedes
and cancel all prior agreements respecting the subject matter hereof (including
without limitation the MRLOA and the letter agreement between JTI and ABX dated
November 1, 1997 relating to the transfer of Transgenic Products or Antibody
Products either written or oral, expressed or implied. No amendment or change
hereof or addition hereto shall be effective or binding on either of the Parties
unless reduced to writing and executed by the respective duly authorized
representatives of ABX and JTI.

[*] 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.

                                       9.



         9.15 COUNTERPARTS. This Agreement may be executed in counterparts, each
of which shall be deemed to be an original and both together shall be deemed to
be one and the same agreement.

         9.16 HEADINGS. The captions to the several Articles and Sections hereof
are not a part of this Agreement, but are included merely for convenience of
reference only and shall not affect its meaning or interpretation.

         IN WITNESS WHEREOF, the Parties have caused this Agreement to be
executed by their respective duly authorized officers as of the day and year
first above written.


         ABGENIX, INC.                                 XENOTECH, INC. AS GENERAL
                                                       PARTNER OF XENOTECH L.P.

         By:/s/ R. Scott Greer                         By:/s/ Raymond M. Withy
            -------------------------------------         ----------------------
            R. Scott Greer                                Raymond M. Withy
            President and Chief Executive Officer         Chairman


         JAPAN TOBACCO INC.


         By:/s/ Takashi Kato
            ------------------------------------------
            Takashi Kato
            Managing Director, Pharmaceutical Division


[*] 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.

                                       10.