When Rick Perry had spinal surgery last month, the Texas governor and potential 2012 hopeful played down his "little procedure," which was aimed at remedying a recurring back ailment.

What Perry didn't disclose, as the Texas Tribune's Emily Ramshaw reports, was that he underwent an experimental procedure that included the injection of his own adult stem cells. It's a therapy that isn't yet approved by the Food and Drug Administration, as doctors have said more testing needs to be done to gauge long-term effects and whether the procedure even works.