CDX-2 is a caudal-related homeobox transcription factor that is expressed by intestinal epithelial cells. CDX-2 is a useful marker for gastrointestinal carcinoma, and for determining the origin of gastrointestinal metastatic adenocarcinoma and carcinoids. Anti-CDX-2 is used for differentiating lung and metastatic colorectal adenocarcinoma, however mucinous ovarian carcinoma also react positively with Anti-CDX-2, thereby limiting the ability to differentiate from metastatic colorectal adenocarcinoma.