Visualization of CLCA4 expression in colorectal cancer tissues by immunohistochemistry. A, Mucosal epithelial cells of normal colonic glans (left) show positive CLCA4 immunostaining, whereas cancer cells in the neoplastic glands show negative immunostaining (right). B and C, Colon cancers shows positive CLCA4 immunostaining in the cancer cells (arrows for positive cells in C). D, Another colon cancer shows negative CLCA4 immunostaining in the cancer cells. E, In a lower concentration of anti-CLCA4 antibody (1/400), the normal mucosal cells show negative CLCA4 immunostaining.