Tissue biopsies from the primary tumor and right groin adenopathies revealed an adenocarcinoma, with positive cytokeratin-7 (CK7), epithelial membrane antigen (EMA), thyroid transcription factor-1 (TTF-1) immunohistochemistry (IHC), and negative cytokeratin-20 (CK20) staining. The gene discussed is MUC1; the disease is adenocarcinoma.