KRT7 and renal cell carcinoma: Immunohistochemistry showed positive staining for cytokeratin 7 (CK7), cytokeratin 19 (CK19), neuron-specific enolase (NSE), α-inhibin and calponin; and negative staining for vimentin, α1-antitrypsin (A1AT), synaptophysin, carcinoembryonic antigen (CEA), renal cell carcinoma stain (RCC), CD10, S-100 protein, and smooth muscle actin.