SAN FRANCISCO, U.S.A, February 24, 2001: Researchers at a California biotechnology company, StemCells Inc., have produced laboratory mice with human brain cells, marking a potential step toward developing treatments for human brain disease like Alzheimer’s but promising to fuel fresh debate over the evolving ethics of bioengineering. “We are not recreating a human brain. We’re really just trying to understand how these stem cells can function, and how they can be used in the treatment of specific diseases,” said Ann Tsukamoto, vice president of scientific operations at StemCells Inc. Irving Weissman, a Stanford university professor involved in the two-year research project, said the next step could be to produce mice with brains made up almost entirely of human cells but a thorough ethical review will be done before this step is taken. Tsukamoto added that the experiment also demonstrated that StemCell Inc’s process was viable, and that cell banks could be established for future transplantation into humans. Both scientists stressed, though their logic may escape the casual reader, that their research was in no way aimed at blurring the lines between human and animal. But consider the bright side. If they develop a talking mouse, Disney can hire, rather than draw, Mickey Mouse.