PDGFRA and rhabdomyosarcoma: Studies have demonstrated the PAX3‐FOXO1 fusion oncoprotein, seen in the majority of patients with fusion‐positive alveolar rhabdomyosarcoma, directly increases PDGFRα expression and, in a preclinical model of fusion‐positive alveolar rhabdomyosarcoma, neutralizing antibodies directed against PDGFRα had antitumor activity.18, 19