According to a news item on Wired News, some mice are able to regrow organs.
Researchers systematically amputated digits and damaged various organs of the mice, including the heart, liver and brain, most of which grew back.
While the quote above does sound cruel, just think of the implications of this if the ability was reproduced in humans (and other animals for that matter).
Of course, it’s not like we could take a bullet to the chest and pass it off like the terminator in T3, but it sure would be nice to be able to replace lost limbs like fingers and toes.
That said, I want to state for the record, that I don’t like to see cruelty to animals.