Wired News - Cells That Go Back in Time:
"Lop off a newt's leg or tail, and it will grow a new one. The creature's cells can regenerate thanks to built-in time machines that revert cells to early versions of themselves in a process called dedifferentiation.
Researchers who study this mechanism hope one day to learn how to induce the same 'cell time travel' in humans. If the cells go back far enough, they become stem cells, which researchers believe hold promise for treating many diseases. Stem cells, which are often taken from embryos, are unformed and have the ability to become many different types of cells. If researchers succeed in inducing this cell time travel, they will also eliminate the ethical issues surrounding embryonic stem-cell research, because no embryos would be destroyed to obtain the cells."
