In childhood cancer, rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma that has been classified into four histological subtypes, in which the alveolar RMS (ARMS) subtype commonly harbor the PAX::FOXO1 fusion gene [PAX3::FOXO1 from t(2;13)(q35;q14); PAX7::FOXO1 from t(1;13)(p36;q14)] and the embryonal RMS (ERMS) subtype is characterized by loss of heterozygosity (LOH) at the 11p15 locus [16, 17]. The gene discussed is FOXO1; the disease is soft tissue sarcoma.