A recent molecular characterization of an ovarian carcinosarcoma patient-derived xenograft revealed p53 and phosphoinositide-3-kinase, catalytic, alpha polypeptide (PIK3CA) mutations, as well as epidermal growth factor receptor overexpression, vascular endothelial growth factor receptor C overexpression and activation of the insulin-like growth factor pathway [27]. The gene discussed is EGFR; the disease is ovarian carcinosarcoma.