March 19, 2013 DAM Holdings, LLC

Exhibit 10.70

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▇▇▇ Holdings, LLC

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Attention: ▇▇▇▇▇▇▇ ▇▇▇▇▇

Re: Credit Agreement with Cancer Genetics, Inc., as amended

Dear ▇▇▇▇▇▇▇:

This letter agreement will memorialize your agreement with respect to that certain Credit Agreement, dated as of March 23, 2011, by and between Cancer Genetics, Inc., a Delaware corporation (the “Company”), and DAM Holdings, LLC (the “Lender”), as amended by that certain Amendment to Credit Agreement, dated March 9, 2012 (as amended, the “Credit Agreement”) and the Promissory Note issued pursuant to the Credit Agreement in the principal amount of $3,000,000, dated March 23, 2011 (the “Note”). The promises set forth in this letter agreement are made to induce us and our underwriters to proceed with the Company’s initial public offering, which is also beneficial to you.

You hereby irrevocably agree to amend Section 8 of the Credit Agreement by replacing the portion of the definition of “Maturity Event” that provides “April 1, 2013” with “August 15, 2013.” Other than as specifically set forth in this letter agreement, all other terms of the Credit Agreement and the Note are and will remain unchanged and in full force and effect.

Very truly yours,
Cancer Genetics, Inc.
By:		/s/ Panna ▇. ▇▇▇▇▇▇
Panna ▇. ▇▇▇▇▇▇
President and CEO

Agreed to and Accepted by:
DAM HOLDINGS, LLC
By:		/s/ ▇▇▇▇▇▇▇ ▇▇▇▇▇
Name:		▇▇▇▇▇▇▇ ▇▇▇▇▇
Title:		President