Arno Therapeutics POS AM Prospectus update (post-effective amendment)

Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the use in this Post-effective Amendment No. 3 to the Registration Statement (No. 333-170474) of Arno Therapeutics, Inc. on Form S-1 of our report dated April 1, 2013, on the financial statements of Arno Therapeutics, Inc. Our report dated April 1, 2013, on the financial statements of Arno Therapeutics, Inc. includes an emphasis paragraph relating to an uncertainty as to the Company’s ability to continue as a going concern.

We also consent to the reference to us under the heading “Experts” in the prospectus.

/s/ Crowe Horwath LLP

New York, New York

May 28, 2012