FOXO1 and alveolar soft part sarcoma: Examples include the PAX3/PAX7–FOXO1 fusion gene in rhabdomyosarcoma (RMS) (Fredericks et al., 1995), the EWSR1 translocation in peripheral primitive neuroectodermal tumor (pPNET) and desmoplastic small round cell tumor (Chen et al., 2016), the TFE3–ASPL fusion gene in alveolar soft part sarcoma (ASPS) (Pradhan et al., 2015), and the SYT–SSX fusion gene in synovial sarcoma (SS) (Sun et al., 2008).