Immunohistochemistry revealed the tumor cells were diffusely and strongly positive for both CK7 and E-cadherin (two blocks stained), positive for PAX-8 (nuclear staining), and negative for c-kit, vimentin, DOG-1, progesterone receptor (PR), carbonic anhydrase IX (Figure 3, panels D, E, F). This evidence concerns the gene KRT7 and neoplasm.