February 18, 2014 Dr. Andrew Pecora

Exhibit 10.66

February 18, 2014

Xx. Xxxxxx Xxxxxx

000 Xxxxx Xxxxxx - Xxxxx 000

Hackensack, New Jersey 07601

Re: Stock Option Modifications.

Dear Xx. Xxxxxx:

This letter agreement will memorialize our understandings with respect to your outstanding stock options following your amicable resignation from the Board of Directors of Cancer Genetics, Inc., (the “Company”), effective as of February 18, 2014.

As of today, you have the following stock options:

Number of options		Issue Date		Exercise Price				Vested Options
15,000		2.19/2009		$	4.00			15,000
10,000		10/10/2013		$	15.39			0
12,000		8/15/2010		$	10.00			12,000

We agree that notwithstanding that the October 10, 2013 stock options are not vested, we will deem them to be vested and exercisable upon your resignation. In addition, notwithstanding any provisions of our equity compensation plans with respect to expiration of options upon termination of service or any other agreements between us, you may exercise all or any part of all three options at any time on or prior to June 30, 2014, at which time all options shall expire. You agree however, that you will not sell any of the shares of common stock of the Company issuable upon the exercise of any such options until May 20, 2014 (or 48 hours after we report earnings for our first fiscal quarter of 2014, if later).

We appreciate you service to the Company and wish you the best in all future endeavors. By execution of this letter, please confirm that you are in agreement with the foregoing and that you have reviewed the Form 8-K announcing your departure from the Board and agree with its content.

Very truly yours,

/s/ Xxxxx X. Xxxxxx

President and CEO

Agreed to and Accepted by:

/s/ Xxxxxx Xxxxxx