Researchers have shown that adult stem cells from one germ layer can be converted into those of another, making adult stem cells at least as useful for cures as [[embryonic stem cells]] might be. For example, adult stem cells have been able to turn marrow cells into heart muscle and blood vessels in humans.{{fact-scientific}} | Researchers have shown that adult stem cells from one germ layer can be converted into those of another, making adult stem cells at least as useful for cures as [[embryonic stem cells]] might be. For example, adult stem cells have been able to turn marrow cells into heart muscle and blood vessels in humans.{{fact-scientific}} |