{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Myogenin is a transcription factor active in muscles. In particular, it is a myogenic regulatory factor. Myogenin is a member of a family of myogenic regulatory genes, which includes MyoD, myf5 and MRF4. These genes encode a set of transcription factors which are essential for muscle development. Expression of myogenin is restricted to cells of skeletal-muscle origin. It is, therefore, a useful marker for tumors of the muscle lineage, being strongly expressed in Alveolar Rhabdomyosarcomas. Anti-myogenin labels the nuclei of myoblasts in developing muscle tissue, and is expressed in tumor cell nuclei of Rhabdomyosarcoma and some Leiomyosarcomas. Positive nuclear staining may occur in Wilm’s Tumor."}]}]}