Release issued 13th May 2002

CLEVELAND, Athersys Inc., a functional genomics and biopharmaceutical company announced today its inclusion in the Red Herring 100 as selected by the editors of Red Herring, the premier magazine of business technology and innovation.

The Red Herring 100 recognizes the top 50 public and the top 50 private companies whose services, business models, products and quality of management define business innovation. It previews the leaders of tomorrow in a number of key technology-related sectors, including software, biotechnology, wireless, communications services, media, hardware, nanotechnology, consumer electronics and energy.

"Athersys is honored to be recognized as a winner of this year's Red Herring 100 award," commented Gil Van Bokkelen, Ph.D., chairman, president and chief executive officer of Athersys. "Being selected as one of Red Herring's top 50 private companies is a testament to Athersys' ability to translate its proprietary platform technologies into a valuable portfolio of products across a number of key therapeutic areas."

In its sixth year, the Red Herring 100 has become the most respected list of its kind. Red Herring editors compile the list by using the same combination of subjective insights and hard metrics favored by venture capitalists and investment bankers. These factors predict a company's ability to disrupt existing markets or create entirely new ones.

The Red Herring 100 is featured in the June 2002 issue of Red Herring magazine and is also available on www.redherring.com. It includes a short profile of Athersys.

Athersys is a functional genomics and biopharmaceutical company engaged in the development, application and commercialization of therapeutic products and novel gene expression tools. The company's research and development programs are focused on its two proprietary platform technologies: RAGE (Random Activation of Gene Expression (tm)) and SMC(tm) (Synthetic Microchromosome(tm)) vector system. RAGE is a

novel gene expression system that provides the unique ability to produce protein from virtually every gene in the human genome, without requiring the cloning of individual genes or use of cDNA libraries. RAGE greatly accelerates the identification and validation of novel drug targets by enabling the direct correlation of a disease process or characteristic with expression of a specific protein. As a result, RAGE has powerful applications in functional genomics; the generation of validated drug targets; discovery of novel antibody drug targets; structural proteomics and rational drug design; and the production of protein therapeutics. Athersys is developing novel therapeutic products based on its proprietary technologies, through partnerships and internal research and development programs. This press release and further information on Athersys, Inc. can be found on the World Wide Web at: www.athersys.com.

Statements herein that are not descriptions of historical facts are forward-looking and subject to risk and uncertainties. Actual results could differ materially from those currently anticipated due to a number of factors, including risks relating to the early stage of products under development; uncertainties related to patent protection; uncertainties relating to clinical trials; dependence on third parties, including strategic partners, collaborators and key personnel; and risks relating to the development and commercialization, if any, of Athersys' proposed products (such as effectiveness of our products, marketing, manufacturing, safety, regulatory, patent or product liability, supply, competition and other risks).

Contacts:

Jeff Steinhilber Chief Financial Officer Athersys, Inc.(216) 431-9900 ext. 250 ir@athersys.com

Michael Lawson Feinstein Kean Healthcare For Athersys, Inc. (617) 577-8110 mlawson@fkhealth.com

(5th August 2002) ATHERSYS EXPANDS PARTNERSHIP WITH BRISTOL-MYERS SQUIBB

(23rd May 2002) Athersys Issued Patent for Secreted Protein Activation, Production

(23rd May 2002) ATHERSYS CO-FOUNDER AND CHIEF SCIENTIFIC OFFICER NAMED ONE OF THE WORLD'S TOP YOUNG INNOVATORS BY TECHNOLOGY REVIEW, MIT'S MAGAZINE OF INNOVATION

(13th May 2002) ATHERSYS ANNOUNCES COMPLETION OF $16.2 MILLION PRIVATE PLACEMENT FINANCING

(13th December 2001) ATHERSYS TO PROVIDE PFIZER WITH DRUG TARGETS