Induced pluripotent stem cells, or iPS cells, resemble embryonic stem cells in their ability to grow into any organ or tissue, but differ in that they can be derived from skin cells, rather than embryos. Kyoto University professor Shin’ya Yamanaka announced in November 2007 that his research team had succeeded in creating iPS cells by implanting four genes into ordinary human skin cells. Because iPS cells do not require embryos, they can sidestep the ethical question of destroying human life. They may someday make regenerative medicine a viable treatment option.