Fat may have finally met its match: laser light. Researchers at the Wellman Center for Photomedicine at Massachusetts General Hospital, Harvard Medical School and the Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab) have shown, for the first time, that a laser can preferentially heat lipid-rich tissues, or fat, in the body without harming the overlying skin. Laser therapies based on the new research could treat a variety of health conditions, including severe acne, atherosclerotic plaque, and unwanted cellulite.