Corporate Profile StemCells, Inc. is a clinical-stage biotechnology company focused on the research, development and commercialization of products derived from stem cell technologies. In its therapeutic product development programs, StemCells is focused on developing cell-based therapeutics to treat diseases of the central nervous system and liver. StemCells’ lead product candidate, HuCNS-SC® cells, are highly purified human neural stem cells which can be expanded and banked until they are delivered as patient doses. StemCells has completed a Phase I clinical trial of HuCNS-SC cells as a potential treatment for neuronal ceroid lipofuscinosis (NCL), a rare and fatal neurodegenerative disease that affects infants and young children. The trial data demonstrated that the HuCNS-SC cells were well tolerated by the trial participants. StemCells has also received approval from the U.S. Food and Drug Administration to initiate a Phase I clinical trial of the HuCNS-SC cells as a potential treatment for Pelizaeus-Merzbacher Disease (PMD), a rare and fatal brain disorder that primarily affects young children. StemCells, through its wholly owned subsidiaries Stem Cell Sciences UK Ltd and Stem Cell Sciences Australia Pty, is also pursuing applications of its cell-based technologies to develop research and drug screening tools, such as cell-based assays, media and reagent tools, which the Company believes represent nearer-term commercial opportunities. StemCells has exclusive rights to approximately 55 issued or allowed U.S. patents and approximately 200 granted or allowed non-U.S. patents. Further information about StemCells is available on its web site at: www.stemcellsinc.com.

Contact Information Address StemCells, Inc. 525 Del Rey Avenue, Suite C Sunnyvale, CA 94085  Phone (408) 731-8670 Fax (408) 731-8674 IR Contact Megan Meloni Director, Investor Relations Home page www.stemcellsinc.com

Corporate Governance Martin McGlynn President and CEO Ann Tsukamoto, Ph.D. Vice President, Research & Development Iris Brest General Counsel Nobuko Uchida Vice President, Stem Cell Biology Barbara Araneo Vice President, Development Pedro Huertas Acting Chief Medical Officer Judi Lum Chief Financial Officer Directors John J. Schwartz, Ph.D. Chairman of the Board, Principal, Quantum Strategies Management Ricardo Levy, Ph.D. Chairman, Catalytica Energy Systems Martin McGlynn President and CEO of StemCells, Inc. Roger Perlmutter, M.D., Ph.D Executive Vice President, Research & Development Irving L. Weissman, M.D. Professor of Cancer Biology, Pathology and Developmental Biology

Shareholder Information Exchange NASDAQ Global Market (.O) Stock Quote (STEM) 1.09  As of 20-Nov-2009 4:00 PM Minimum 20 minutes delayed Listed Security STEM Common Stock Corporate Counsel Ropes & Gray One International Place Boston, MA 02110