FOXO1 and soft tissue sarcoma: Alveolar rhabdomyosarcoma (RMA) is a highly malignant pediatric soft tissue sarcoma entity, predominantly characterized by the oncogenic fusion gene forkhead box protein O1 (FOXO1) from chromosome 13 with either paired box protein 3 or 7 (PAX3, PAX7) from chromosome 2 or 1 [t(2;13)(q35;q14) or t(1;13)(p36;q14)] (1–3).