ARMS are typically PAX3-FOXO1 (60%) or PAX7-FOXO1 (20%) fusion-positive RMS characterized by the poorest prognosis; however, promising results to arrest tumor progression have been obtained using targeted inhibitors destabilizing the PAX3-FOXO1 oncoprotein in animal models. Here, FOXO1 is linked to alveolar rhabdomyosarcoma.