{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"MyoD belongs to a family of proteins known as myogenic regulatory factors (MRFs) and has a key role in regulating muscle differentiation. These bHLH (basic helix loop helix) transcription factors act sequentially in myogenic differentiation. MyoD is expressed in activated satellite cells, but not in quiescent satellite cells. In development, MyoD commits mesoderm cells to a skeletal lineage, and then regulates that process. It may also play a role in muscle repair. MyoD expression in rhabdomyosarcoma cells reflects their commitment to the myogenic lineage, as reported in the literature."}]}]}