EXHIBIT 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in the following Registration Statements:

(1)Registration Statement (Form S-8, No. 333-267497) dated September 19, 2022 pertaining to the Athersys, Inc. 2019 Equity and Incentive Compensation Plan,

(2)Registration Statement (Form S-8, No. 333-263710) dated March 18, 2022 pertaining to the Nonqualified Stock Option Inducement Agreement,

(3)Registration Statement (Form S-3, No. 333-257409) dated June 25, 2021,

(4)Registration Statement (Form S-3, No. 333-244384) dated August 11, 2020,

(5)Registration Statement (Form S-3, No. 333-238810) dated May 29, 2020,

(6)Registration Statement (Form S-8, No. 333-237318) dated March 20, 2020 pertaining to the Senior Vice President Inducement Award,

(7)Registration Statement (Form S-3, No. 333-235945) dated January 16, 2020,

(8)Registration Statement (Form S-8, No. 333-235946) dated January 16, 2020 pertaining to the Macleod Nonqualified Stock Option Inducement Award,

(9)Registration Statement (Form S-3, No. 333-234715) dated November 15, 2019,

(10)Registration Statement (Form S-8, No. 333-232075) dated June 12, 2019 pertaining to the Athersys, Inc. 2019 Equity and Incentive Compensation Plan,

(11)Registration Statement (Form S-3, No. 333-222828) dated February 2, 2018,

(12)Registration Statement (Form S-8, No. 333-212119) dated June 20, 2016 pertaining to the Amended and Restated 2007 Long-Term Incentive Plan,

(13)Registration Statement (Form S-3, No. 333-208629) dated December 18, 2015,

(14)Registration Statement (Form S-8, No. 333-189406) dated June 18, 2013 pertaining to the Athersys, Inc. Amended and Restated 2007 Long-Term Incentive Plan (Amended and Restated Effective June 18, 2013), and

(15)Registration Statement (Form S-8, No. 333-175023) dated June 20, 2011 pertaining to the Athersys, Inc. Amended and Restated 2007 Long-Term Incentive Plan (Amended and Restated Effective June 16, 2011),

(16)Registration Statement (Form S-8, No. 333-147379) dated November 14, 2007 pertaining to the Athersys, Inc. Equity Incentive Compensation Plan, and

(17)Registration Statement (Form S-8, No. 333-147380) dated November 14, 2007 pertaining to the Athersys, Inc. Long-Term Incentive Plan;

of our reports dated March 31, 2023, with respect to the consolidated financial statements of Athersys, Inc. included in this Annual Report (Form 10-K) of Athersys, Inc. for the year ended December 31, 2022.

/s/ ERNST & YOUNG LLP

Cleveland, Ohio

March 31, 2023