It sounds like science fiction, but scientists may have just taken a giant step toward a future where amputees regrow real limbs. Researchers studying axolotl salamanders, zebrafish and mice say they’ve uncovered a powerful set of genes that appear to control regeneration itself. The breakthrough, published in the Proceedings of the National Academy of Sciences , could one day help scientists develop therapies that regrow living tissue, bone and even entire arms and legs in humans. “This