Tracking down powerful adult stem cells in mouse testes may benefit humans, too Researchers say they have found a way to pluck out a potent type of stem cell from the testes of adult mice and transform it into other kinds of tissue, including heart muscle and blood vessels. The result—the second such finding in the past year—suggests that similar cells from human testicles might have similar powers, paving the way to creating replacement tissue for men who have suffered damage from heart attacks or other injuries and avoiding some of the controversy surrounding embryonic stem cells (ESC). Three separate...