Document:

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                                                                   Exhibit 10.27

[INCYTEGENOMICS LETTERHEAD]

October 18, 2001

Patrick Plewman
Chief Executive Officer
diaDexus, Inc.
343 Oyster Point Blvd.
South San Francisco, CA 94080

Dear Patrick:

This letter is intended to amend and clarify the Collaborative Agreement (the
"Agreement"), effective as of September 2, 1997 entered into by and between
diaDexus, Inc., a Delaware corporation having its principal place of business
at 343 Oyster Point Blvd., South San Francisco, California 94080, the successor
in interest to diaDexus LLC ("diaDexus"), and Incyte Genomics, Inc., a Delaware
corporation having its principal place of business at 3160 Porter Drive, Palo
Alto, California 94304, the successor in interest to Incyte Pharmaceuticals,
Inc. ("Incyte").

All capitalized terms not defined in this letter shall have the meaning set
forth in the Agreement.

1.   All references to Incyte Pharmaceuticals in the Agreement are replaced
with Incyte Genomics as the successor in interest to Incyte Pharmaceuticals and
all references to diaDexus, LLC are replaced with diaDexus, Inc. as the
successor in interest to diaDexus, LLC.

2.   Paragraph 3.6(b), line 6, is hereby amended to add the phrase "and
3.6(d)," after the phrase "and 3.4.2(d) with respect to exclusive licenses
granted".

3.   A new Paragraph 3.6(d) is hereby added as follows:

(d)  Sublicensing Drug Product(s) to Third Party Collaborators.
     ----------------------------------------------------------

     On an individual Drug Product-by-Drug Product basis, diaDexus may grant a
     sublicense to any third party under the rights granted to diaDexus
     hereunder with
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     respect to any Drug Product(s), including without limitation with respect
     to the Incyte Database Technology relating to such Drug Product(s), to
     clinically develop, make, use, offer to sell, sell, import, export and
     distribute such Drug Product; provided that (i) such Drug Product(s) is the
     subject of an Investigational New Drug application submitted to the United
     States Food and Drug Administration or an equivalent thereto to any agency,
     (ii) diaDexus has paid Incyte the IND (or equivalent) milestone payment in
     accordance with Section 4.2 prior to grant of such sublicense, (iii) any
     such sublicense is granted together with a grant of rights under
     intellectual property, owned or otherwise held by diaDexus, relating to
     such Drug Product(s) acquired as a result of research and development by or
     on behalf of diaDexus, and (iv) sublicensing rights are provided solely
     with respect to those rights which Incyte has the right to grant diaDexus;
     and (v) sublicensing rights may be granted solely to the extent that such
     sublicense is required by such third party in order to clinically develop,
     make, use, sell, offer to sell, import, export or distribute such diaDexus
     Product, (vi) diaDexus shall be responsible for any and all milestone
     payments and royalties due to Incyte pursuant to Article 4.0 as a
     consequence of such sublicense. diaDexus shall obtain the written
     commitment of any sublicensee to abide by all applicable terms and
     conditions of this Agreement. Promptly upon execution of any permitted
     sublicense, diaDexus shall provide notice thereof to Incyte and reasonable
     satisfactory evidence that such sublicense is in compliance with this
     Section 3.6.

     Any sublicensing outside of (i)-(iv) above, except as otherwise expressly
     provided in this Agreement, is strictly prohibited, including without
     limitation any rights to sublicense Gene Product(s) for use as research
     tools or in database products.

4.   Incyte agrees that diaDexus, pursuant to Section 5.3, may utilize
consultants, academic collaborators and third party collaborators that may or
may not be LifeSeq subscribers (individually and collectively "Collaborators")
to conduct research and development with respect to Designated Gene Products,
including without limitation Designated Gene Products subject to an option
pursuant to Sections 3.4.1 or Section 3.4.2, to discover and evaluate Drug
Products, Antisense Products and Therapeutic Protein Products. Incyte further
agrees that diaDexus may agree to grant a sublicense to Collaborators with
respect to (1) any Drug Product discovered as a result of a collaboration with
such Collaborators in accordance with Section 3.6(b) or Section 3.6(d), and
other applicable provisions of the Agreement, and (2) any Antisense Products or
Therapeutic Protein Products discovered as a result of a collaboration with such
Collaborators in accordance with Sections 3.6(b), and other applicable
provisions of the Agreement.
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Any and all provisions of the Agreement not expressly modified by this letter
shall remain in full force and effect.

Sincerely,

Incyte Genomics, Inc.

By signing this letter, the parties have executed an amendment to the Agreement
effective as of the Effective Date.

DIADEXUS, INC.

By:  /s/ Patrick Plewman
   ----------------------------

Name:  Patrick Plewman
     --------------------------

Title:   President & CEO
      -------------------------

Date:    10/18/01
     --------------------------To:            Alok Mohan

From:          Doug Michels

Date:          November 26, 2001

Subject:       Consulting Agreement

As we have discussed, the continuation of your consulting agreement with the
Company is important to Tarantella's success. We have agreed to maintain your
current terms for the next calendar year. As in 2001, this agreement is based on
25% of your time.

       -      Term of the agreement shall be for one year commencing January 1,
              2002 and will be renewable by mutual agreement of both parties
              with approval by the Compensation Committee.

       -      As compensation for your consulting services to Tarantella, you
              shall receive a fee targeted at $180,000 per year paid as
              follows:

              -      $90,000 annually (paid monthly at $7500 per month) as a
                     retainer for your services.

              -      $90,000 annually (paid quarterly) as a target incentive.
                     Incentive payments shall be made solely based upon
                     Tarantella's performance against its Revenue and Operating
                     Income measures paid in accordance with the provisions of
                     the Tarantella Management Incentive Plan.

              -      In accordance with Tarantella's's policy, as an ex-CEO and
                     member of Tarantella's Board of Directors, you will
                     continue to be covered under the Company's medical, dental
                     and vision plans. There will be no coverage for life
                     insurance or disability due to your change in status from
                     an employee.

This agreement supercedes any and all prior agreements between you and the
Company. Compensation paid to you will be in lieu of other compensation normally
accorded to members of the Company's Board of Directors. While covered under
this agreement you will specifically not receive compensation for your
participation on the Board or for attendance at committee meetings and/or board
meetings and will not be entitled to additional stock options granted to board
members on an annual basis.

By signing below, I am agreeing to the provisions of this agreement and waive my
right to receive such compensation and stock options as normally accorded
members of the Board.

------------------------------                            ---------------
Agreed: Alok Mohan                                             Date<PAGE>

                                                                   EXHIBIT 10.28

                           LOAN MODIFICATION AGREEMENT

        This Loan Modification Agreement is entered into as of February 22,
2001, by and between Talarian Corporation ("Borrower") and Silicon Valley Bank
("Bank").

1. DESCRIPTION OF EXISTING INDEBTEDNESS: Among other indebtedness which may be
owing by Borrower to Bank, Borrower is indebted to Bank pursuant to, among other
documents, an Amended and Restated Loan and Security Agreement, dated August 6,
1998, as may be amended from time to time, (the "Loan Agreement"). The Loan
Agreement provided for, among other things, a Committed Revolving Line in the
original principal amount of One Million Dollars ($1,000,000). The Loan
Agreement was modified, pursuant to, among other things, a Loan Modification
Agreement dated February 22, 2000, pursuant to which, among other things, the
Committed Revolving Line was increased to Two Million Dollars ($2,000,000).
Defined terms used but not otherwise defined herein shall have the same meanings
as in the Loan Agreement.

Hereinafter, all indebtedness owing by Borrower to Bank shall be referred to as
the "Indebtedness".

2. DESCRIPTION OF COLLATERAL AND GUARANTIES. Repayment of the Indebtedness is
secured by the Collateral as described in the Loan Agreement and by the
Intellectual Property Collateral as described in that certain Intellectual
Property Security Agreement, dated July 11, 1997, by and between Borrower and
Bank.

Hereinafter, the above-described security documents and guaranties, together
with all other documents securing repayment of the Indebtedness shall be
referred to as the "Security Documents". Hereinafter, the Security Documents,
together with all other documents evidencing or securing the Indebtedness shall
be referred to as the "Existing Loan Documents".

3. DESCRIPTION OF CHANGE IN TERMS.

        A. Modification(s) to Loan Agreement

                1 The following term defined under Section 13.1 entitled
                  "Definitions," is hereby amended to read as follows:

                  "Revolving Maturity Date" is February 22, 2002.

4. CONSISTENT CHANGES. The Existing Loan Documents are hereby amended wherever
necessary to reflect the changes described above.

5. PAYMENT OF LOAN FEE. Borrower shall pay Bank a fee in the amount of Seven
Thousand Five Hundred and 00/100 Dollars ($7,500.00) ("Loan Fee") plus all
out-of-pocket expenses.

6. NO DEFENSES OF BORROWER. Borrower (and each guarantor and pledgor signing
below) agrees that, as of the date hereof, it has no defenses against the
obligations to pay any amounts under the Indebtedness.

7. CONTINUING VALIDITY. Borrower (and each guarantor and pledgor signing below)
understands and agrees that in modifying the existing Indebtedness, Bank is
relying upon Borrower's representations, warranties, and agreements, as set
forth in the Existing Loan Documents. Except as expressly modified pursuant to
this Loan Modification Agreement, the terms of the Existing Loan Documents
remain unchanged and in full force and effect. Bank's agreement to
modifications to the existing Indebtedness pursuant to this Loan Modification
Agreement in no way shall obligate Bank to make any future modifications to the
Indebtedness. Nothing in this Loan Modification Agreement shall constitute a
satisfaction of the Indebtedness. It is the intention of Bank and Borrower to
retain as liable parties all makers and endorsers of Existing Loan Documents,
unless the party is expressly released by Bank in writing. No maker, endorser,
or guarantor will be released by virtue of this Loan Modification Agreement. The
terms of this paragraph apply not only to this Loan Modification Agreement, but
also to all subsequent loan modification agreements.

8. CONDITIONS. The effectiveness of this Loan Modification Agreement is
conditioned upon payment of the Loan Fee.

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        This Loan Modification Agreement is executed as of the date first
written above.

BORROWER:                                   BANK:

TALARIAN CORPORATION                        SILICON VALLEY BANK

By: /s/ MICHAEL A. MORGAN                   By: [SIGNATURE ILLEGIBLE]
   --------------------------------            ---------------------------------
Name: Michael A. Morgan                     Name: [NAME ILLEGIBLE]
      -----------------------------               ------------------------------
Title: CFO                                  Title: VP
       ----------------------------                -----------------------------

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