KRT7 and colonic neoplasm: Because of this, although some studies argue that the loss of CDX2 is prevalent among dysplastic and malignant cells of gastric cancer and suggested the same rule for colonic tumors [13], newer studies contradict these findings and identify CDX2 antibody as a useful tumor marker specific for neoplasia of intestinal origin, although not as specific as CK7/CK20 [11, 12, 14].