As a fusion gene found in alveolar rhabdomyosarcoma (ARMS), the PAX3-FOXO1 fusion occurs in about 60% of patients with ARMS, causing the 5-year survival rate of less than 30%–50% for patients with this fusion-positive RMS (FP-RMS) (37). The gene discussed is FOXO1; the disease is alveolar rhabdomyosarcoma.