Exhibit 10.7

Volume Discount Addendum No. 2

This
2ndVolume Discount Addendum to the Purchase Agreement
(the 2ndAddendum) is effective as of
April 1, 2011 (the 2ndAddendum Effective
Date), by and between diaDexus, Inc. (diaDexus), and Health Diagnostics Laboratory located at 737 N. 5th Street, Richmond, VA 23219 and any or all of its subsidiaries or affiliates (Lab).

WHEREAS, Lab and diaDexus are parties to that certain Purchase Agreement dated January 1, 2011 (the
PA) and the Volume Discount Addendum thereto dated January 1, 2011 (the 1stAddendum), collectively the Agreement;

WHEREAS, the parties desire to amend such 1stAddendum to make Product available to Lab directly from diaDexus.

NOW THEREFORE, in consideration of the agreements, mutual representations and covenants contained herein and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereby agree as follows:



|1. | Definitions. All capitalized terms not defined herein shall have the meaning assigned to them in the Agreement.
|-- | ---------------------------------------------------------------------------------------------------------------



|2. | Product Supply. Beginning on the 2ndAddendum Effective Date, Lab shall order Products directly from diaDexus pursuant to the terms and conditions of the
Agreement.
|-- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------



|3. | Program. diaDexus shall be responsible for all aspects of the Program previously fulfilled by diaDexus distributor.
|-- | --------------------------------------------------------------------------------------------------------------------



|4. | 1stAddendum Continuance. Except as set forth above, the 1stAddendum remains in full force and effect, including the Program, Net Reimbursement review, and the Program Term.
|-- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------



|5. | Entire Agreement. In the event of any conflict between the terms and conditions of this
2ndAddendum and the Agreement, the terms and conditions
of this 2ndAddendum shall control. Except as otherwise
provided in the 2ndAddendum, the parties agree that all
provisions of the 2ndAgreement are hereby ratified and
agreed to be in full force and effect and are incorporated herein by reference. This 2ndAddendum and the Agreement (as amended hereby), including without limitation all addenda, contain the entire agreement among the parties relating to the subject matter herein and all prior proposals,
discussions and writings by and among the parties and relating to the subject matter herein, whether written or oral, are superseded hereby and thereby. None of the terms of this 2ndAddendum shall be deemed to be amended unless such amendment is in writing, signed by all parties hereto, and recites
specifically that it is an amendment to the terms of this
2ndAddendum.
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IN WITNESS WHEREOF, the parties hereto have caused this 2ndAddendum to be executed by their fully authorized representatives.



|                         |  |  |  |                               
|------------------------ |  |  |  | ------------------------------
|diaDexus, Inc.:          |  |  |  | Health Diagnostics Laboratory:
|                         |  | 
|By: /s/ Patrick Plewman  |  |  |  | By: /s/ Tonya Mallory         
|Name: Patrick Plewman    |  |  |  | Name: Tonya Mallory           
|Title: President and CEO |  |  |  | Title: President and CEO      
|                         |  | 
|Date: 4/19/11            |  |  |  | Date: 4/19/11                 



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