PAX3 and alveolar rhabdomyosarcoma: In a review [125] following the publication of the animal model [47], Keller et al. discuss the possibilities for the cell of origin for ARMS; because Keller et al. achieved the formation of ARMS tumors in their mouse model using Myf6-Cre-driven conditional PAX3-FOXO1, and Myf6 is usually expressed in differentiating skeletal muscle myotubes, they propose a potential dedifferentiation mechanism for ARMS development.