Cadherin 17 is a novel diagnostic marker for adenocarcinomas of the digestive system.

Cadherin 17 is a member of a multigene family of calcium-dependent, transmembrane proteins that mediates cell-cell adhesion, plays important roles during embryogenesis, and is crucial for tissue morphogenesis and maintenance. Cadherin 17 is exclusively expressed in the epithelial cells of embryonic and adult small intestine and colon, and pancreatic ducts. It has also been reported to be frequently expressed in adenocarcinomas arising in the gastrointestinal tract and pancreas. Owing to its restricted expression in these groups of tumors, cadherin 17 has proven to be a useful immunohistochemical marker for assisting in distinguishing these neoplasms from other malignancies with which they may be confused.