Embryonic stem cells can differentiate into the three "germ layers": ectoderm, endoderm and mesoderm. The 220 types of cells in humans are all based on these germ layers. Some scientists, particularly those having pro-choice political views, claim that embryonic stem cells can differentiate better, and divide into greater numbers, than [[adult stem cells]] can.
But there hasn't yet been a single clinical trial showing any success from embryonic stem cells. Moreover, even if were possible to provide cures (which is unprovennot yet proven), then an approved cure based on embryonic stem cells would be at least ten years away.[citation needed]