Context:
The researchers don't know whether the reprogramming they are seeing is initiated by the low pH or by some other type of stress, such as chemical changes
happening further down the line. But they think they are tapping into a fundamental body-repair process. If you injure cells significantly enough, so that they almost die, certain genes get switched on or off, says Vacanti. This may result in a change in the cell's overall controls, meaning all genes have the potential to be switched on again. This could happen in all tissues throughout the body, Vacanti says. "Perhaps injuries like a bump on the arm or a burn cause mature cells to revert back to stem cells."
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http://www.newscientist.com/article/mg22129542.500-stem-cell-power-unleashed-after-30-minute-dip-in-acid.html?page=2