Tissue regeneration therapies in mammals is progressing at an impressive pace. Everyone who's ever looked into the field knows that vertebrates lower on the evolutionary ladder are capable of regrowing lost limbs and organs, like salamanders and axolotls, but higher lifeforms really can't. The best that humans can do is putting things back more or less they way they were, a process that we all know as healing. Once something's gone, though, it's gone (save for the liver, which can infact regrow if a small portion of liver tissue remains and the rest of the body is properly cared for …