Scientists have just created living laser light out of a human cell and some jellyfish protein, but it's not quite as terrifying as it sounds. Developed by Malte Gather and Seok Hyun Yun at Massachusetts General Hospital, the new technique revolves around something known as green fluorescent protein (GFP) -- a naturally glowing molecule found in jellyfish that can be used to illuminate living material. After genetically engineering a human kidney cell to express this protein, Gather and Yun wedged it between two mirrors in an inch-long cylinder, filled with a GFP solution. Then, they infused the system with blue light, until the cell began to emit its own pulses of bright green laser light. Researchers also noticed that the cell could regenerate any destroyed fluorescent proteins, potentially paving the way for scientists to conduct light-based therapy and medical imaging without an external laser source. Hit the source link for more information, though you'll need a subscription to Nature Photonics to access the full article.