MyoD1 is a member of the myogenic regulatory factors(MRFs) protein family and plays a crucial part in controllingmuscle differentiation. During myogenic development,these bHLH (basic helix loop helix) transcription factorsfunction in a sequential manner. Activated satellite cellsexpress the MyoD1 antibody, but quiescent satellite cellsdo not. MyoD1 commits mesoderm cells to a skeletallineage during development and then controls thatprocess. It might be involved in muscle healing as well.One of the first indicators of myogenic commitment inaberrant tissues is the MyoD1 antibody, which identifiestumour cells in rhabdomyosarcoma.