Description

CDX2 is used in diagnostic surgical pathology as a marker for gastrointestinal differentiation, especially colorectal. Hepatocellular carcinomas show no expression of CDX2. CDX2 expression can be seen, however, in selected non-GI adenocarcinomas such as mucinous ovarian carcinomas and adenocarcinomas of the urinary bladder.

Cytokeratin 7 is a basic cytokeratin and is expressed in epithelial cells of ovary, lung and breast, but not in the colon or gastrointestinal tract. It is often used in conjunction with Cytokeratin 20 in distinguishing pulmonary ovarian and breast carcinomas (CK7 +) from colon carcinomas (CK7-).

Multiplex cocktail of CDX2 and CK7 can be used to distinguish colon cancers from breast, lung and ovarian cancers. CDX-2 will stain the nuclei brown and CK7 will stain target antigens red.