CDX2 is a homeobox gene encoding nuclear homeodomain transcriptional factor essential to intestinal organogenesis. CDX2 is crucial for differentiation of epithelium in the intestine, pancreas and biliary tract. CDX2 interacts with the tumour suppressor genes APC and E-cadherin, as well as bcl-2.In the intestine (from duodenum to rectum) CDX2 nuclear protein is demonstrated strongly and uniformly in all types of epithelial cells. In pancreas and biliary tract CDX2 protein is demonstrated in scattered ductal cells. In tumor tissues, CDX2 is positive in the large majority cases of colorectal and appendiceal adenocarcinomas.CDX2 is a relatively sensitive and specific marker for “intestinal” adenocarcinomas. In the classification of (adeno-)carcinomas of the unknown primary, CDX2 is an important marker but should always be included in a panel. Also in order to identify the origin of neuroendocrine tumors, CDX2 is useful in a panel.
Synthetic peptide corresponding to CDX2 residues within aa1‐100 of CDX2 was used as an immunogen.