Researchers have determined that the TFIID protein complex controls the stem cell genes that repair skeletal muscle. This image shows differentiated human skeletal muscle fibers (myotubes, in green) protecting the MyoD protein (colored in red), which cooperates with TFIID to transform muscle stem cells into muscle tissue. Cell nuclei are stained blue. This discovery could help develop strategies that activate stem cells to repair muscles degenerated by aging or diseases like muscular dystrophy and cancer.