Twenty-five days. That's how long it took Dr. Shinya Yamanaka of
Kyoto University to undo more than 30 years of exquisitely
programmed biology packed into a woman's cheek cell and just
maybe change the world. In a procedure that some scientists
thought could take decades to discover, Yamanaka tricked the
cheek cell into acting like an embryonic stem cell capable of
dividing, developing and maturing into any of the body's more
than 200 different cell types. And he wasn't alone: on the same
day that he published his milestone in the journal Cell, James
Thomson, a pioneering University of Wisconsin molecular
biologist, reported similar success in Science. Their papers cap
a year of remarkable research, in which scientists have surged
ahead of ethicists and politicians in finding ever more clever
ways to generate stem cells. But where other breakthroughs
relied on using cells from living embryos tiny bits of inchoate
life, fraught with ethical issues the work by Yamanaka and
Thomson sidesteps that abyss by nursin