 Cells that make myogenic bHLH transcription factors (including MyoD or Myf5) are committed to development as a muscle cell.Consequently, the simultaneous deletion of Myf5 and MyoD also results in a complete lack of skeletal muscle formation.Research has shown that MyoD directly activates its own gene; this means that the protein made binds the "myoD" gene and continues a cycle of MyoD protein production.