Rare Bone Disease (IMAGE) University of Pennsylvania School of Medicine Caption Microscopic image of tooth-derived stem cells from an FOP patient acquired through the "Good Tooth Fairy" program at the Perelman School of Medicine at the University of Pennsylvania. Credit Josef Kaplan. PhD, Perelman School of Medicine, University of Pennsylvania Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.