PAX3 and alveolar rhabdomyosarcoma: PAX3-FOXO1, the fusion gene that is a risk factor for poor prognosis, acts as a super-enhancer dependent on the BET bromodomain protein, BRD4 (bromodomain-containing protein 4), which suggests BRD4 as a treatment target for alveolar rhabdomyosarcoma patients with the PAX3-FOXO1 translocation [53].