Snippet from the article:
Researchers have found that the gene p21 appears to block the healing power still enjoyed by some creatures including amphibians but lost through evolution to all other animals. By turning off p21, the process can be miraculously switched back on.
Academics from The Wistar Institute in Philadelphia found that mice lacking the p21 gene gain the ability to regenerate lost or damaged tissue. Unlike typical mammals, which heal wounds by forming a scar, these mice begin by forming a blastema, a structure associated with rapid cell growth.
Read the full article — Humans could regrow body parts like some amphibians
Essentially, their research shows that blocking this gene will cause cells to act like stem cells, which would allow them to create new tissue rather than just heal the damaged tissue. This, of course, is incredibly early research and has not been studied in humans. We’ll see where this goes.