Myogenin belongs to a family of myogenic transcription factors, including MyoD, myf5, and MRF4, which are critical in muscle development. Myogenin is found strictly in cells of skeletal muscle origin, and is therefore used as a biomarker for tumors of the muscle lineage, including alveolar rhabdomyosarcomas. Anti-Myogenin staining may occur in Wilms’ tumor, and labels the nuclei of myoblasts in developing muscle tissue. It is also expressed in some leiomyosarcomas.