Immunostaining for cytokeratin (CK) 7, CK20 and Ki-67 confirmed that CK7: (−), CK20: (+) and Ki-67: (<=30%) in villous adenoma while CK7: (+), CK20: (+), and Ki-67: (70%) in urothelial carcinoma. This evidence concerns the gene KRT7 and villous adenoma.