MUC1 and basal cell carcinoma: AR, androgen receptor; BCC, basal cell carcinoma; CEA, carcinoembryonic antigen; CK, cytokeratin; DTE, desmoplastic trichoepithelioma; EMA, epithelial membrane antigen; MAC, microcystic adnexal carcinoma; MBCC, morphea basal cell carcinoma; PHLDA1, pleckstrin homology-like domain family A member 1; PKK1, pan-cytokeratin.