EGFR, RAS, Cyclin D1, P16 and P53 are particularly helpful when trying to distinguish the histologically similar malignant BT from high grade serous carcinoma with solid, pseudo-endometrioid and transitional cell carcinoma-like features, as the latter is usually positive for P16 and P53 while negative for EGFR, RAS, and Cyclin D1 (Table 3) [29]. The gene discussed is CDKN2A; the disease is serous adenocarcinoma.