<PAGE>

                                           * TEXT OMITTED AND FILED SEPARATELY
                                              CONFIDENTIAL TREATMENT REQUESTED
                                         UNDER 17 C.F.R. SECTIONS 200.80(b)(4)
                                                           200.83 AND 230.406.


                  MICROBIAL DATAFLOW SOFTWARE LICENSE AGREEMENT


                                     BETWEEN


                           ELITRA PHARMACEUTICALS INC.


                                       AND


                              INCYTE GENOMICS, INC.



<PAGE>

               MICROBIAL DATAFLOW SOFTWARE LICENSE AGREEMENT


         THIS AGREEMENT is entered into as of this 30th day of June, 2000 (the
"EFFECTIVE DATE") by and between ELITRA PHARMACEUTICALS INC. ("ELITRA"), a
Delaware corporation, having its principal place of business at 3510 Dunhill
Street, San Diego, CA 92121, and INCYTE GENOMICS, INC. ("INCYTE"), a Delaware
corporation, having its principal place of business at 3160 Porter Drive, Palo
Alto, CA 94304.

         WHEREAS, Incyte has developed and owns certain computer software
providing analysis and data-management tools for handling complex information
from multiple sources; and

         WHEREAS, ELITRA desires to implement such software at ELITRA; and

         WHEREAS, this Microbial Dataflow Software License Agreement shall not
be considered valid or binding without execution by both Incyte and ELITRA of
the Microbial Information Agreement of even date herewith; and

         NOW, THEREFORE, Incyte and ELITRA, intending to be legally bound,
hereby agree as follows:

1.       DEFINITIONS.

         When used in this Agreement, the following definitions shall apply:

         "DOCUMENTATION" shall mean the user's manuals provided to ELITRA along
with the Microbial Dataflow Software.

         "ELITRA AFFILIATE(S)" shall mean any company or entity controlled by,
controlling, or under common control with ELITRA shall include any company one
hundred percent (100%) of whose voting stock or participating profit interest is
owned or controlled, directly or indirectly, by ELITRA, and any company which
owns or controls, directly or indirectly, one hundred percent (100%) of the
voting stock of ELITRA.

         "ELITRA FIELD OF USE" shall mean the field of microbial genomics,
including, without limitation, that of fungal and bacterial pathogens.

         "INCYTE TECHNOLOGY" shall mean Intellectual Property Rights claiming or
covering the use of the Microbial Dataflow Software to the extent owned or
controlled by Incyte and which Incyte has an unrestricted right to license
without obligation of payment to a third party.

         "INSTALLATION SITE" shall mean the research facilities of ELITRA and/or
any ELITRA Affiliate which will have access to the Microbial Dataflow Software
subject to this Agreement.

         "INTELLECTUAL PROPERTY RIGHTS" shall mean all copyrights, trademarks,
service marks, trade secrets, patents, patent applications, moral rights,
contract rights and other proprietary rights.


                                       1


<PAGE>


         "MICROBIAL DATAFLOW AGREEMENT" shall mean that certain Software
License Agreement dated [...***...] between Incyte and [...***...] as such
agreement relates to the Microbial Dataflow Software.

         "MICROBIAL DATAFLOW SOFTWARE" shall mean (a) Incyte's set of
proprietary software modules, as of the Effective Date, used by Incyte in
processing microbial data, as described generally in EXHIBIT A and (b) any
updates or improvements to, or products substantially constituting replacements
of, the foregoing.

         "MICROBIAL DATAFLOW SOURCE CODE" shall mean the source code written for
the Microbial Dataflow Software.

         "PARTY" shall mean ELITRA or Incyte and, when used in the plural, shall
mean ELITRA and Incyte.

         "SOFTWARE" as generally used herein shall mean software in various
stages of development or any product thereof and includes without limitation the
literal elements of a program (source code, object code, manuals, instructions
or otherwise), its audiovisual components (menus, screens, structure and
organization), any human or machine readable form of the program, and any
writing or medium in which the program or information therein is stored, written
or described, including without limitation, diagrams, flow charts, designs,
drawings, specifications, models, data, development tools and routines, bug
reports and customer information.

2.       LICENSE GRANT; SOFTWARE USE RESTRICTIONS AND SECURITY REQUIREMENTS.

         2.1      LICENSES TO ELITRA. Subject to the terms and conditions of
this Agreement, Incyte hereby grants to ELITRA:

                           (a)      an exclusive (except as set forth below),
worldwide, fully-paid, perpetual and irrevocable (unless terminated under
Section 5.2) license, with the right to sublicense solely as set forth in
Section 2.2 below, under the Microbial Dataflow Software in the ELITRA Field
of Use; PROVIDED, HOWEVER, that the exclusivity of the foregoing license
shall be subject to the following rights which are expressly retained by
Incyte: (i) to use the Microbial Dataflow Software to [...***...] (ii) to use
Microbial Dataflow Software solely to the extent necessary to [...***...]; (iii)
to use the Microbial Dataflow Software to [...***...]; and (iv) to use the
Microbial Dataflow Software to [...***...]

                           (b)      the right to make up to [...***...]
copies of the Microbial Dataflow Software solely for backup or archival
purposes.

                                       2
                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         2.2      MICROBIAL DATAFLOW AGREEMENT. Incyte shall retain all
right, title and interest in and to the Microbial Dataflow Agreement. From
and after the Effective Date of this Agreement, Incyte shall not [...***...]
pursuant to the Microbial Dataflow Agreement, which agreement expires as of
[... *** ...]. Incyte further agrees that it shall [...***...] nor shall
Incyte [...***...] with respect to the [...***...] At least [... *** ...],
Incyte shall provide [...***...]. To the extent that [...***...].

         2.3      OWNERSHIP. ELITRA hereby acknowledges that (a) Incyte has
expended significant resources and efforts to develop the Microbial Dataflow
Software; (b) the Microbial Dataflow Software represents highly valuable and
confidential assets of Incyte; (c) Incyte is willing to grant ELITRA access to
the Microbial Dataflow Software in reliance that ELITRA shall protect such
Software from unauthorized disclosure and use; and (d) the Microbial Dataflow
Software at all times during the term of this Agreement shall remain the sole
and exclusive property of Incyte.

         2.4      RESERVATION OF RIGHTS. Subject to the grant of license rights
ELITRA hereunder, the Microbial Dataflow Software and all proprietary rights,
title, and other intellectual property rights, including, without limitation,
patent, copyright, trademark, service mark, trade secret and trade name rights,
in and to such Microbial Dataflow Software are hereby owned by Incyte.

         2.5      RESTRICTIONS ON USE AND DISCLOSURE OF SOFTWARE.

                  2.5.1    DESIGNATED CPU'S. The Microbial Dataflow Software
shall only be installed at each Installation Site on a single hard disk(s) or
the hard disk(s) of a designated file server whereby multiple workstation(s) do
not contain copy(s) of the Microbial Dataflow Software installed, other than
ephemerally, on the workstation hard disk. A back-up computer or file server may
be designated such that a copy of the Microbial Dataflow Software may be
installed on this computer in the event that the primary computer fails. Under
no circumstances will the Microbial Dataflow Software be installed on any
designated CPU(s) which would allow unauthorized network access (E.G., third
party access via the Internet). All other access to the Microbial Dataflow
Software, including access by facilities of ELITRA and ELITRA Affiliates other
than those designated as Installation Sites, is prohibited.

                  2.5.2    NON-DISCLOSURE. Except as expressly provided herein,
ELITRA shall not disclose the Microbial Dataflow Software, the Microbial
Dataflow Software Source Code or


                                       3

                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>


Confidential Information of Incyte or transfer the Microbial Dataflow
Software, or any portion thereof or modifications thereto, to any third party.

                  2.5.3    NO TRANSFER OR MODIFICATION. Except as expressly
provided herein, ELITRA shall not sublicense, sell, assign, convey, transfer,
publish, display, copy, duplicate, adapt, merge, embed, disassemble, decompile,
translate, reverse engineer or otherwise modify any portion of the Microbial
Dataflow Software (by any means whatsoever whether now known or hereafter
invented). Notwithstanding the foregoing, ELITRA shall have the right (a) to
modify the Microbial Dataflow Software for its internal use and (b) to
sublicense the Microbial Dataflow Software to Monsanto Company in accordance
with Section 2.2.

                  2.5.4    LOSS OR THEFT. ELITRA promptly shall notify Incyte of
any loss, theft or unauthorized disclosure or use of Microbial Dataflow Software
which comes to ELITRA's attention.

         2.6      IMPROVEMENTS AND UPDATES TO MICROBIAL DATAFLOW SOFTWARE. To
the extent that Incyte is obligated to provide improvements or updates to the
Microbial Dataflow Software or any component thereof [...***...], or Incyte
otherwise develops improvements or updates to the Microbial Dataflow
Software, Incyte shall [...***...].

3.       INTELLECTUAL PROPERTY.

         3.1      THIRD PARTY INTELLECTUAL PROPERTY. Subject to the
warranties made hereunder as to each Party's knowledge of any third party
rights that may be infringed by the uses of the Microbial Dataflow Software
as contemplated herein, ELITRA acknowledges that, [...***...] ELITRA
[...***...], and it is hereby agreed that it shall be [...***...], if
necessary, [...***...]. SCHEDULE 3.1 attached hereto is a true and complete
list of third party software programs which are required for ELITRA to access
and utilize the Microbial Dataflow Software.

         3.2      DELIVERY AND ACCEPTANCE. Incyte shall deliver the Microbial
Dataflow Software, the Microbial Dataflow Source Code and the related
Documentation to ELITRA upon execution of this Agreement. The Microbial Dataflow
Software and the Microbial Dataflow Source Code shall be delivered on a CD-ROM
and/or on such other media as the Parties shall mutually agree depending upon
the nature and format of the information being transferred.

4.       PAYMENTS.

         4.1      FEES; PAYMENT TERMS. Payments for access and perpetual license
to the Microbial Dataflow Software and other related payment are included under
Article 4 of the Microbial Information Agreement.


                                       4
                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

5.       TERM; TERMINATION.

         5.1      TERM. This Agreement shall commence as of the Effective Date
and shall continue in full force and effect unless terminated as provided
herein.

         5.2      TERMINATION FOR BREACH. Material failure by either Party to
comply with any of its obligations under this Agreement shall entitle the other
Party to give to the Party in default written notice specifying the nature of
the default and requiring it to cure such default. If such default is not cured
within sixty (60) days after the receipt of such notice, the notifying Party
shall be entitled, without prejudice to any of its other rights conferred on it
by this Agreement, in addition to any other remedies available to it by law or
in equity, immediately to terminate this Agreement by giving notice to the other
Party. The right of a Party to terminate this Agreement, as hereinafter
provided, shall not be affected in any way by its waiver or failure to take
action with respect to any previous default.

         5.3      EFFECT OF TERMINATION. In the event of termination of the
Agreement by Incyte for breach by ELITRA, then it shall be ELITRA's obligation,
at its expense, to discontinue use of the Microbial Dataflow Software and remove
the Microbial Dataflow Software from each designated CPU, and promptly return
any copies thereof to Incyte, or upon Incyte's written instruction, destroy all
portions and copies of the Microbial Dataflow Software, and thereafter
relinquish its rights to the Microbial Dataflow Software, including any rights
to use, copy, modify, adapt, create derivative works with respect to same.

         5.4      DISPUTE RESOLUTION PROCEDURES. If the Parties cannot resolve a
dispute arising out of or in connection with this Agreement, then any Party may,
by written notice to the other, have such dispute referred to their respective
officers designated below or their respective successors, for attempted
resolution by good faith negotiations within 30 days after such notice is
received:

                           For Incyte:               President

                           For ELITRA:               President

         Any such dispute which is not so resolved between the Parties or the
designated officers of the Parties within such 30 day period shall, upon written
notice from a Party to the other, be resolved by final and binding arbitration
under then current Licensing Agreement Arbitration Rules of the American
Arbitration Association ("AAA"). If the claim is filed by a Party, the venue for
arbitration shall be proximate to that of the other Party. The arbitration shall
be conducted by a panel of three arbitrators who are knowledgeable in the
subject matter which is at issue in the dispute (the "PANEL"). Each Party shall
have the right to appoint one member of the Panel, with the third member to be
mutually agreed by the two Panel members appointed by the Parties, or, failing
such agreement, shall be selected according to the AAA rules. In conducting the
arbitration, the Panel shall determine what discovery will be permitted,
consistent with the goal of limiting the cost and time which the Parties must
expend for discovery (and provided that the Panel shall permit such discovery
deemed necessary to permit an equitable resolution of the dispute). The decision
of the Panel shall be in writing and shall set forth the basis therefor. The
Parties shall abide by all awards rendered in arbitration proceedings, and such
awards may be


                                       5
<PAGE>

enforced and executed upon in any court having jurisdiction over the Party
against whom enforcement of such award is sought. The Panel shall also determine
the steps, if any, that a Party should take to correct any failure or breach by
such Party pertaining to any such dispute. The Parties shall share equally the
Panel's fees and expenses. The decision of the Panel shall be final and may be
enforced by the Party in whose favor it runs in any court of competent
jurisdiction at the option of such Party. Nothing in this Agreement shall be
deemed to prevent either Party from seeking injunctive relief (or any other
provisional remedy) from any court having jurisdiction over the Parties and the
subject matter of the dispute as necessary to protect either Party's
intellectual property rights.

         5.5      ACCRUED RIGHTS; SURVIVING OBLIGATIONS. Termination of this
Agreement for any reason shall be without prejudice to any rights which shall
have accrued to the benefit of either Party prior to such termination. Upon any
termination of this Agreement, the following provisions will not terminate, but
will continue in full force and effect: Article 2 (License Grant; Software Use
Restrictions and Security Requirements), except that Section 2.1 shall not
survive if Incyte has terminated this Agreement for breach by ELITRA; Section
3.1 (Third Party Intellectual Property); Article 5 (Term; Termination); Section
6.4 (Disclaimers); Article 7 (Indemnity); Article 8 (Miscellaneous Provisions);
and any payment obligations pursuant to ELITRA's rights which have become due
and payable under the appropriate sections of this Agreement prior to the
termination or expiration of this Agreement.

6.       REPRESENTATIONS AND WARRANTIES; COVENANTS.

         6.1      REPRESENTATIONS AND WARRANTIES OF INCYTE. Incyte represents
and warrants to ELITRA as follows:

                           (a)      Incyte has full corporate power and
authority to enter into this Agreement and to perform its obligations hereunder.
The execution and delivery of this Agreement and the consummation of the
transactions contemplated hereby have been duly authorized by all necessary
corporate action on the part of Incyte. This Agreement has been duly executed
and delivered by Incyte and constitutes a valid and binding obligation of
Incyte, enforceable against it in accordance with its terms.

                           (b)      Neither the execution, delivery nor
performance of this Agreement by Incyte will conflict with or result in the
breach of any agreement to which Incyte is a party or any instrument, document,
law, regulation, judgment, order or decree by which it or its assets are bound.

                           (c)      There are no material adverse proceedings,
claims or actions pending, or to the best of Incyte's knowledge, threatened,
relating to the Incyte Technology as of the Effective Date of this Agreement
which would materially interfere with Incyte's performance of its obligations
under this Agreement. Further, Incyte shall disclose to ELITRA any material
adverse proceedings, claims or action that arise and come to the knowledge of
Incyte without undertaking a special investigation, relating to Incyte
Technology, which would materially interfere with Incyte's performance of its
obligations under this Agreement.


                                       6
<PAGE>

                           (d)      Incyte is the [...***...], and [...***...]
 . Incyte is [...***...]. Except as set forth on Schedule 3.1, Incyte is
[...***...].

                           (e)      Incyte requires [...***...], and
requiring [...***...] made within the [...***...] pursuant to [...***...].

                           (f)      For a period of [...***...] after
[...***...] is provided to [...***...]. This warranty does not apply to
[...***...].

                           (g)      Incyte hereby represents and warrants to
ELITRA that [...***...].

                           (h)      The term [...***...] means any [...***...]
to (a) [...***...] or (b) [...***...]. Incyte represents and warrants that the
Microbial Dataflow Software and the media on which the [...***...]. Without
limiting this warranty, [...***...] will use a [...***...]. ELITRA
acknowledges that [...***...]. Incyte's sole obligation if [...***...], will
be to [...***...].

                                       7
                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

         6.2      REPRESENTATIONS AND WARRANTIES OF ELITRA. ELITRA represents
and warrants to Incyte as follows:

                           (a)      ELITRA has full corporate power and
authority to enter into this Agreement and to perform its obligations hereunder.
The execution and delivery of this Agreement and the consummation of the
transactions contemplated hereby have been duly authorized by all necessary
corporate action on the part of ELITRA. This Agreement has been duly executed
and delivered by ELITRA and constitutes a valid and binding obligation of
ELITRA, enforceable against it in accordance with its terms.

                           (b)      Neither the execution, delivery nor
performance of this Agreement by ELITRA will conflict with or result in the
breach of any agreement to which ELITRA is a party or any instrument, document,
law, regulation, judgment, order or decree by which it or its assets are bound.

         6.3      COMPLIANCE WITH LAW. Each Party shall be responsible for
compliance with all applicable product safety, product testing, product
labeling, package marking, and product advertising laws and regulations with
respect to its own activities and commercial products. Further, ELITRA and
Incyte shall each comply with the regulations of the United States and any other
relevant jurisdiction concerning any export or other transfer of technology,
services, or products.

         6.4      DISCLAIMERS.

                           (a)      EXCEPT AS OTHERWISE PROVIDED IN THIS
AGREEMENT, INCYTE DOES NOT MAKE ANY AND EXPRESSLY DISCLAIMS ALL WARRANTIES WITH
RESPECT TO THE MICROBIAL DATAFLOW SOFTWARE, WHETHER ORAL OR WRITTEN, EXPRESS OR
IMPLIED, OR ARISING BY USAGE OF TRADE OR COURSE OF DEALING INCLUDING, WITHOUT
LIMITATION, THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE.

                           (b)      EXCEPT AS EXPLICITLY STATED HEREIN, NEITHER
PARTY WILL BE LIABLE FOR ECONOMIC, INCIDENTAL, CONSEQUENTIAL, INDIRECT, SPECIAL
OR EXEMPLARY DAMAGES, WHETHER CLAIMED UNDER CONTRACT, TORT OR ANY OTHER LEGAL
THEORY ARISING FROM SUCH PARTY'S ACTIVITIES UNDER THIS AGREEMENT.

7.       INDEMNITY.

         7.1      INDEMNIFICATION BY INCYTE. Incyte shall indemnify and hold
ELITRA and its directors, officers, employees, agents, representatives and
affiliates harmless from and against any loss, liability, cost or expense
(including, but not limited to, reasonable attorneys' fees and costs) arising
from (i) [...***...], or (ii) [...***...]; except to the extent such loss,
liability, cost or expense (including attorney's fees and costs) is

                                       8
                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

attributable to: (a) a violation of law, regulation or court order by ELITRA,
(b) a violation of any contractual or fiduciary duty (including
misappropriation of trade secrets) owed by ELITRA to a third party, (c)
recklessness or intentional misconduct of ELITRA, (d) any breach of this
Agreement or misrepresentation contained herein by ELITRA, or (e)
infringement by ELITRA (other than by use of the Microbial Dataflow Software
or any portion thereof) of any third party's patent rights, copyrights or
other intellectual property rights.

         7.2      INDEMNIFICATION BY ELITRA. ELITRA shall indemnify and hold
Incyte and its directors, officers, employees, agents, representatives and
affiliates harmless from and against any loss, liability, cost or expense
(including, but not limited to, reasonable attorneys' fees and costs) arising
from [...***...] except to the extent such loss liability, cost or expense
(including attorney's fees and costs) is\ attributable to: (i) a violation of
law, regulation or court order by Incyte, (ii) a violation of any contractual
or fiduciary duty (including misappropriation of trade secrets) owed by
Incyte to a third party, (iii) recklessness or intentional misconduct of
Incyte, (iv) any breach of this Agreement or misrepresentation contained
herein by Incyte, or (v) infringement by Incyte of any third party's patent
rights, copyrights or other intellectual property rights.

         7.3      INDEMNIFICATION PROCEDURES. If any claim is made against
either Party under Sections 7.1 or 7.2 above for which indemnification is
available hereunder, the indemnifying Party, at its option, shall:

                           (a)      defend the other Party against such claim;

                           (b)      acquire for the other Party the right to
continue using any Software or product licensed hereunder that is the subject of
such claim;

                           (c)      replace any Software or product licensed
hereunder with other Software or product for which there exists no infringement
claim, which serves materially the same purpose and function as the claimed
infringing Software or product; or

                           (d)      modify the Software or product to make it
non-infringing;

PROVIDED, HOWEVER, that no Party shall have any liability or obligation to the
other under this Section 7.3 if any such infringement claim is based upon or
arises out of:

                           (a)      any modification by the indemnified Party of
any portion of any Software or data not authorized by the indemnifying Party in
writing unless without such modifications the Software would be infringing;

                           (b)      the use of the any Software or product in
violation of the license granted in this Agreement; or

                           (c)      a patent, copyright or other intellectual
property right claim in which the indemnified Party or any affiliate thereof has
any direct or indirect interest by license or otherwise; or


                                       9
                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

                           (d)      use of old Software after receipt or
replacement of modified Software under (iii) or (iv) above.

If the indemnifying Party elects (i) above, the indemnifying Party, at its
expense, shall have the right to control the defense and settlement of any
such claim and the indemnified Party shall reasonably cooperate with the
indemnifying Party, at the indemnifying Party's expense, in such defense and
settlement. If the indemnifying Party elects (iii) above, the indemnified
Party shall return to the indemnifying Party the claimed infringing Software
or product, along with any copies, duplicates and other manifestations
thereof in whatever form.

This Section 7.3 states a Party's entire liability and obligation, and the
other Party's exclusive remedy, for infringement with respect to the first
Party's software.

8.       MISCELLANEOUS PROVISIONS.

         8.1      NO PARTNERSHIP. Nothing in this Agreement is intended or
shall be deemed to constitute a partnership, agency, distributorship,
employer-employee or joint venture relationship between the Parties. No Party
shall incur any debts or make any commitments for the other, except to the
extent, if at all, specifically provided herein.

         8.2      ASSIGNMENTS. Neither Party shall assign any of its rights
or obligations hereunder except: (i) [...***...] (ii) in the case of
[...***...] to any of [...***...], and in either case, provided that the
[...***...], as applicable; (iii) with respect to either Party [...***...],
provided that the [...***...]; (iv) [...***...]. This Agreement shall be
binding, upon the successors and permitted assigns of the Parties. Any
assignment not in accordance with the above shall be void. To the extent that
any assignment by ELITRA hereunder would directly result in an increase in
any withholding taxes for which Incyte is responsible under this Agreement,
ELITRA shall be responsible for such additional taxes.

         8.3      NO TRADEMARK RIGHTS. Except as otherwise provided herein, no
right, express or implied, is granted by this Agreement to use in any manner the
names "Incyte" or "ELITRA", or any other trade name or trademark of Incyte or
ELITRA or their affiliates in connection with the performance of this Agreement.

         8.4      PUBLIC ANNOUNCEMENTS. Any and all public announcements
concerning this Agreement or the subject matter hereof shall be governed by the
provisions of Section 8.4 of the Microbial Information Agreement.

         8.5      ENTIRE AGREEMENT OF THE PARTIES; AMENDMENTS. This Agreement
and the other agreements between the Parties of even date herewith constitute
and contain the entire understanding and agreement of the Parties and cancel and
supersede any and all prior


                                      10
                                            *CONFIDENTIAL TREATMENT REQUESTED
<PAGE>

negotiations, correspondence, representations, understandings and agreements,
whether verbal or written, between the Parties respecting the subject matter
hereof, including, without limitation, the Prior Agreement and all financial
obligations of ELITRA to Incyte thereunder (whether or not accrued as of the
Effective Date hereof); PROVIDED, HOWEVER, that the Confidential Disclosure
Agreement between the Parties dated March 31, 2000 shall remain in full force
and effect in accordance with its terms. No waiver, modification or amendment of
any provision of this Agreement shall be valid or effective unless made in
writing and signed by a duly authorized officer of each of the Parties.

         8.6      APPLICABLE LAW. This Agreement shall be governed by and
interpreted in accordance with the laws of the State of California, without
reference to the conflicts of law principles thereof. The parties expressly
exclude application of the United Nations Convention for the International Sale
of Goods.

         8.7      NOTICES AND DELIVERIES. Any notice, requests, delivery,
approval or consent required or permitted to be given under this Agreement shall
be in writing and shall be deemed to have been sufficiently given if delivered
in person, transmitted by commercial overnight courier, or transmitted by telex
telegram or telecopy (facsimile, with confirmed receipt) to the Party to whom it
is directed at its address shown below or such other address as such Party shall
have last given by notice to the other Party (referred to herein as "notice").
All notices shall be effective upon receipt.

         If to Incyte, addressed to:

                  Incyte Genomics, Inc.
                  3160 Porter Drive
                  Palo Alto, CA  94304
                  Fax: (650) 845-4574
                  Attn:  Roy Whitfield, Chief Executive Officer

         If to ELITRA, addressed to:

                  ELITRA Pharmaceuticals Inc.
                  3510 Dunhill Street
                  San Diego, CA  92121
                  Fax: (858) 410-3810
                  Attn:  Harry Hixson, Ph.D., Chief Executive Officer and
                         Chairman

         8.8      AFFILIATE PERFORMANCE. To the extent that any ELITRA Affiliate
has access to the Microbial Dataflow Software, has the right to receive any
other rights or benefits under this Agreement or otherwise is obligated to
perform any obligations under this Agreement, ELITRA shall cause such ELITRA
Affiliate to perform in full, when due, all applicable obligations under this
Agreement to the same extent as if such ELITRA Affiliate were a party to this
Agreement; provided, however, that nothing in this Section 8.8 shall expand the
rights or benefits of ELITRA or ELITRA Affiliates, or the obligations of Incyte,
beyond those otherwise expressly set forth in this Agreement. ELITRA shall
guaranty timely performance in full by such ELITRA Affiliate of


                                      11

<PAGE>

all such obligations. A breach by such ELITRA Affiliate of any such
obligation shall constitute a breach by ELITRA of this Agreement.

         8.9      COUNTERPARTS. This Agreement may be executed in any number of
counterparts, each of which shall be deemed an original and all of which
together shall constitute one and the same instrument.


                                      12

<PAGE>

         IN WITNESS WHEREOF, the Parties have caused this Agreement to be
executed by their respective duly authorized officers as of the Effective Date.


                                      INCYTE GENOMICS, INC.



                                      By: /s/ Randy Scott
                                         --------------------------------------

                                      Name: Randy Scott
                                           ------------------------------------

                                      Title: President
                                            -----------------------------------

                                      Date: 6/30/00
                                           ------------------------------------


                                      ELITRA PHARMACEUTICALS INC.



                                      By: /s/ Harry Hixson, Jr.
                                         --------------------------------------

                                      Name: Harry F. Hixson, Jr.
                                           ------------------------------------

                                      Title: Chief Executive Officer
                                            -----------------------------------

                                      Date: 6/30/00
                                           ------------------------------------


                               SIGNATURE PAGE TO
                 MICROBIAL DATAFLOW SOFTWARE LICENSE AGREEMENT

<PAGE>

                                    EXHIBIT A

                           MICROBIAL DATAFLOW SOFTWARE


[... *** ...]


                                     A-1.      *CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

[... *** ...]


                                     A-2.      *CONFIDENTIAL TREATMENT REQUESTED