These cells were focally positive with hCG, p53, p40, sal-like protein 4 (SALL4), placental alkaline phosphatase (PLAP), CD146 and epithelial membrane antigen (EMA) staining, which indicated a choriocarcinoma (Fig. 5c, d, f–h, m, n). This evidence concerns the gene MUC1 and choriocarcinoma.