November 7, 2003

News Release: StemCells Inc. Preclinical Data Offers Hope for Multiple Sclerosis and Spinal Cord Injury

StemCells, Inc. (Nasdaq: STEM) today announced positive results of a preclinical study using the Company's human neural stem cells (hCNS-SC) to regenerate myelin, a nerve fiber insulator that is often lost or damaged in spinal cord injury, multiple sclerosis and certain genetic disorders. Dr. Stan Tamaki, Ph.D., Senior Scientist at StemCells, Inc., will present these findings at the 33rd Annual Society for Neuroscience Meeting in New Orleans taking place November 8-12, 2003.

Results of the study show extensive myelination of nerve axons in a mouse that cannot produce myelin because it lacks a functional copy of the basic myelin protein gene. The mouse is known as the 'shiverer'mouse model because the absence of myelin in the nerves of the spinal cord produces shivering behavior. Dr. Tamaki will present evidence that the Company's hCNS-SC, when transplanted into the shiverer mouse, generate human oligodendrocytes that functionally integrate into the brain and produce myelin, resulting in widespread insulation of the mouse nerve axons.

'Damage to myelin is the primary factor responsible for the extensive muscle and organ malfunction associated with conditions such as spinal cord injury and multiple sclerosis,'said Dr. Tamaki. 'By regenerating healthy myelin producing oligodendrocytes, we may potentially be able to alleviate these symptoms that so many patients suffer from.'

Since destruction of myelin also occurs in spinal cord injury, the data obtained from the 'shiverer'mouse study helps elucidate the mechanism of functional recovery seen in a previously reported preclinical spinal cord injury study sponsored by StemCells Inc. In a collaborative endeavor with Drs. Aileen J. Anderson and Brian J. Cummings of the Reeve-Irvine Center at the University of California, Irvine, StemCells Inc.'s hCNS-SC were evaluated in mice with spinal cord injuries. Transplanted injured mice showed improved motor function in comparison with controls. Moreover, the degree of functional recovery was directly linked to the level of human cell engraftment. Additional data from these studies will be presented by the Company's collaborators at the SFN meeting.

The deficiency of functional myelin is also characteristic of many lysosomal storage disorders, such as Krabbe's, Metachromatic Leukodystrophy, and Tay-Sachs disease. The Company has previously reported on the preclinical efficacy of its cells for treatment of Neuronal Ceroid Lipofuscinosis, a lysosomal storage disease commonly referred to as Batten's Disease. Transplantation of the Company's hCNS-SC into the brains of Batten mice resulted in a significant reduction in the amount of stored waste material and protection of neuronal cells from further loss. An update of this study will be the subject of a presentation by the Company's collaborators at the SFN meeting.

'StemCells has now established, in live animal models, that its human neural stem cell gives rise to the three major cell types of the central nervous system, i.e. neurons, astrocytes and oligodendrocytes. Above all, we have shown that these derivative cells function and behave accordingly. With these recent results, we believe we are definitively moving closer to being able to treat a wide array of diseases or injuries to the brain and spinal cord,'said Martin McGlynn, President and CEO of StemCells.

About StemCells, Inc.

StemCells, Inc is a biotechnology company focused on the discovery, development and commercialization of stem cell-based therapies to treat diseases of, or injury to, the nervous system, liver, and pancreas. The Company's stem cell programs seek to repair or repopulate neural or other tissue that has been damaged or lost as a result of disease or injury. Further information about the Company is available on its web site, at www.stemcellsinc.com.

Statements in this press release other than statements of historical facts constitute forward-looking statements regarding, among other things, the future business operations of StemCells, Inc. ('the Company'). The forward- looking statements speak only as of the date of this news release. StemCells does not undertake to update any of these forward-looking statements to reflect events or circumstances that occur after the date hereof. Such statements reflect management's current views and are based on certain assumptions that may or may not ultimately prove valid. The Company's actual results may vary materially from those contemplated in the forward looking statements due to risks and uncertainties to which the Company is subject, including the risk that Company will not be successful in using the patented technologies to develop effective treatments for human diseases; uncertainties regarding the Company's ability to obtain the capital resources needed to conduct the research, preclinical development and clinical trials necessary for regulatory approvals; the fact that the Company's stem cell technology is at the pre-clinical state and has not yet led to the development of any proposed product; the uncertainty whether the preclinical work mentioned above will be replicable in another animal model and whether comparable results will be obtainable in humans; the uncertainty whether any products that may be generated in the future in the Company's stem cell programs will prove clinically effective and not cause tumors or other side effects; the uncertainty whether the Company will achieve revenues from product sales or become profitable; and others that are described in Exhibit 99 to the Company's Annual Report on Form 10-K entitled 'Cautionary Factors Relevant to Forward Looking Statements.'

Corporate Contact:
Media / Investor Relations Contact: StemCells, Inc.
The Investor Relations Group, Inc.
Martin McGlynn, President &CEO
Janet Vasquez / Jane Lin
650-475-3100, ext 108
212-825-3210

SOURCE StemCells, Inc.

Martin McGlynn, President &CEO of StemCells, Inc., +1-650-475-3100, ext 108; or Media

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