CONFIRMING STATEMENT
This Statement confirms that the undersigned, Cancer Prevention and
Research Institute of Texas, has authorized and designated each of Wayne R.
Roberts and Heidi M. McConnell to execute and file on the undersigned's behalf
all Forms 3, 4, and 5 (including any amendments thereto) that the undersigned
may be required to file with the U.S. Securities and Exchange Commission as a
result of the undersigned's ownership of or transactions in securities of Mirna
Therapeutics, Inc. The authority of Wayne R. Roberts and Heidi M. McConnell
under this Statement shall continue until the undersigned is no longer required
to file Forms 3, 4, and 5 with regard to the undersigned's ownership of or
transactions in securities of Mirna Therapeutics, Inc., unless earlier revoked
in writing. The undersigned acknowledges that neither Wayne R. Roberts nor Heidi
M. McConnell is assuming any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934.
Date: October 7, 2015 Cancer Prevention and Research Institute
of Texas
By: /s/ Wayne R. Roberts
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Name: Wayne R. Roberts
Title: Chief Executive Officer
Cancer Prevention & Research Institute of Texas Inactive
Filed: 8 Oct 15, 12:00am