NEWARK, Calif., Oct. 12, 2012 (GLOBE NEWSWIRE) -- StemCells, Inc. (Nasdaq:STEM) today announced the issuance of U.S. Patent Number 8,283,164 titled "Liver engrafting cells, assays, and uses thereof." The patent broadly covers purified populations of human liver cells, including the Company's human liver engrafting cells (hLEC). hLEC cells were first isolated by Company researchers in the late 1990s, and Company scientists have repeatedly demonstrated the cells' engraftment and robust bioactivity in vivo and that they are expandable. While the Company's hLEC cells are purified from donated adult livers not suitable for transplant, the newly issued '164 patent importantly claims cells independent of tissue source. Therefore, the '164 patent has potential relevance to those deriving liver cells from iPS or ESC platforms. The term of the '164 patent extends into 2022. "This new patent extends our IP protection around hLEC cells and should be of interest to those searching for an expandable human liver cell," said Martin McGlynn, President and Chief Executive Officer of StemCells, Inc. "Because the liver is such a key organ, finding an expandable, reliable and well-characterized liver cell population is an important step forward in both medical research and drug development. For example, liver disease afflicts some 25 million Americans and transplantation of an expandable liver cell could potentially address many of the shortcomings of whole liver transplantation. Moreover, the right liver cells could make profound contributions to drug screening and toxicity testing." In October 2011, StemCells formed a wholly-owned subsidiary to focus on both the therapeutic and research tool applications of its hLEC technologies and to serve as an investment vehicle for those interested in a "pure play" liver cell company. The '164 patent is one of several patents issued to the Company on a worldwide basis claiming expandable liver cells, including U.S. Patent Nos. 7,811,818 and 7,211,404, Japan Patent No. 4445876, Australian Patent No. 2002315392, and European Patent No. 1406998. Patent prosecution in the family is ongoing on a worldwide basis, including China application 02816528.4.