When a kid lops off a fingertip with a cleaver or car door, there's a chance the end of the digit will grow back. The fingerprint will be gone, and the tip may look a bit strange. But the flesh, bone and nail could return.
Now biologists at New York University have figured out just how this lizard-like regeneration happens in mice. There's some secret sauce at the nail cuticle that makes it possible, scientists report Wednesday in the journal Nature.