Scientists keep finding new ways to play with cells and make them alter their behavior, even their identity. First came the remarkable work of Shinya Yamanaka at Kyoto University, who showed it was possible, by activating just four genes, to take a mature cell (he used a bit of skin but other cells would work) and turn it into the equivalent of an embryonic stem cell with the potential to become any other cell in the body of mouse or human.
