MUC1 and melanoma: The tumor cells were negative for the expression of pan-cytokeratin (PCK), cytokeratin (CK) 5/6 (CK5/6), P40, CK7, CK8/18, epithelial membrane antigen (EMA), thyroid transcription factor 1 (TTF-1), synaptophysin (Syn), neuron-specific enolase, AFP, glypican-3, CD30, placental alkaline phosphatase (PLAP), CD117, D2-40, melan-A, human melanoma black-45 (HMB-45), S-100, sex-determining-region-Y-box transcription factor 10 (SOX10), CD99, paired box transcription factor 8, desmin, alpha-smooth muscle actin, leucocyte common antigen (LCA), CD3, CD20, anaplastic lymphoma kinase (ALK), and CD138.