Common diagnostic examples include Ewing sarcoma with the characteristic EWSR1-FLI1 fusion, alveolar rhabdomyosarcoma distinguished from other rhabdomyosarcomas by the PAX3/7-FOXO1 fusion, and synovial sarcoma with its pathognomonic SS18-SSX1/2/4 fusion. The gene discussed is FOXO1; the disease is rhabdomyosarcoma.