Exhibit 16.1
[LETTERHEAD OF GRANT THORNTON LLP]
September 25, 2013
U.S. Securities and Exchange Commission
Office of the Chief Accountant
100 F Street, NE
Washington, DC 20549
Re: Osiris Therapeutics, Inc.
File No. 001-32966
Dear Sir or Madam:
We have read Item 4.01 of Form 8-K of Osiris Therapeutics, Inc. dated September 25, 2013, and agree with the statements concerning our Firm contained therein.
Very truly yours,
/s/ GRANT THORNTON LLP