"I've tried to look at all the published references and especially the science," he says. And in his opinion, these show little evidence that embryonic stem cells will work as medical treatments. For starters, he claims, James Thomson of the University of Wisconsin at Madison, one of the discoverers of human embryonic stem cells, has "actually said that cloning will not be of any clinical significance." Moreover, "mouse embryonic stem cells have been around since 1981," he points out. "But to date, when (scientists) leave the cells in culture, they have not been able to generate every cell type that exists in the body." Instead of chasing an undeveloped and potentially dangerous Holy Grail, he says, scientists should concentrate on using adult stem cells (a position that, not coincidentally, dovetails perfectly with President Bush's). Adult stem cells transplanted into small groups of people with Parkinson's disease and multiple sclerosis have yielded promising results.