Paget cells express Cytokeratin 7 (CK7), Cytokeratin 5.2, carcinoembryonic antigen, gross cystic disease fluid protein 15, human epidermal growth factor receptor 2, carbohydrate antigen 125, and androgen receptors, but do not express markers of squamous cell differentiation, such as p63 and p40, and melanocyte markers, such as Melan-A, Human Melanoma Black-45, or S100 proteins. The gene discussed is KRT7; the disease is melanoma.