Clumsy manicurists can thank a set of stem cells under the base of the fingernail for erasing their mistakes. Those cells allow not only trimmed fingernails but amputated fingertips to regrow. Doctors could one day use nail stem cells to treat malformed nails or even amputated limbs, Mayumi Ito of New York University Langone Medical Center suggests.
Scientists have long known that children and some adults can regrow the tips of their fingers after amputation. But digits can’t regenerate if more than the nail region is amputated.