Exhibit 10.1

AMENDMENT NO. 2

to

ASSIGNMENT AGREEMENT

This AMENDMENT TO ASSIGNMENT AGREEMENT ("Amendment"),
effective as of March 2, 2009 (the "Amendment Date"), is made and entered into by and between
PHARMACYCLICS, INC., a Delaware corporation having a place of business at 995 East Arques Avenue, Sunnyvale,
California 94085, ("Pharmacyclics") and CELERA CORPORATION having a place of business at 1401
Harbor Bay Parkway, Alameda, California 94502 ("Celera").  Pharmacyclics and Celera may each be referred to
herein individually as a "Party" or, collectively, as "Parties."

WHEREAS, Applera Corporation, through its Celera Group, entered into an assignment agreement
with Pharmacyclics, effective as of April 7, 2006, whereby the Celera Group assigned to Pharmacyclics certain proprietary
technology and know-how related to the Celera Programs, including but not limited to the HDAC Program (the "Original
Assignment Agreement");

WHEREAS, Pharmacyclics and the Applera Corporation, through its Celera Group, subsequently
executed Amendment No. 1 to the Original Assignment Agreement, effective May 12, 2008, in order to amend certain payment terms of
the Assignment Agreement relating to [***] [***] (the "First Amendment") (the Original Assignment Agreement, as
amended by the First Amendment, hereinafter the "Assignment Agreement");

WHEREAS, The Celera Groupwas
spun out of the Applera Corporation in July 2008 to create the Celera Corporation, and the Assignment Agreement was assigned by the
Applera Corporation to the newly formed Celera Corporation;

WHEREAS, Pharmacyclics desires that certain terms of the Assignment Agreement should be
amended; and

WHEREAS, Celera desires that such terms should be amended, subject to the terms and conditions
set forth below

NOW, THEREFORE, in consideration of the mutual covenants and obligations set forth herein, and for
other good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, Pharmacyclics and Celera hereby
agree as follows:

1. In General.

|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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1. Amendment of the Assignment Agreement.

|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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1. Reference to and Effect on the Assignment Agreement.


3.1   Pursuant to Section 13.1 of the Assignment Agreement, this Amendment shall be effective upon the
Amendment Date, whereupon the Assignment Agreement shall be, and hereby is, amended as set forth herein.
3.2   On and after the Amendment Date, each reference in the Assignment Agreement to "this
Agreement," "hereunder," "hereof," "herein" or words of like import shall mean and be a
reference to the Assignment Agreement as amended hereby.  No reference to this Amendment need be made in any instrument or
document at any time referring to the Assignment Agreement, a reference to the Assignment Agreement in any of such to be deemed
to be a reference to the Assignment Agreement as amended hereby.
3.3   All provisions of the Assignment Agreement not expressly modified by this Amendment shall remain in full
force and effect.
2. Counterparts.

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

|PHARMACYCLICS, INC. ("Pharmacyclics")


By: /s/ Robert Duggan Print Name: Robert Duggan Title: CEO & Chairman |  | CELERA CORPORATION ("Celera")


By: /s/ Stacey Sias   Print Name: Stacey Sias Title: VP & Chief Business Officer
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|*** | Indicates that material has been omitted and confidential treatment has been requested, therefore all such omitted
material has been filed separately with the Commission pursuant to Rule 246-2.
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