Description: Carcino-embryonic Antigen (CEA, CD66e) family glycoproteins are present in epithelial cells and tumors (both benign and malignant) of various types (gastrointestinal, bronchial mucosa, breast, pancreas, biliary duct). CEA is synthesized during development in the fetal gut, and re-expressed in increased amounts in intestinal carcinomas and several other tumors. Tis antibody to CEA is useful in identifying the origin of various metastatic adenocarcinomas and in distinguishing pulmonary adenocarcinomas (60 to 70% are CEA+) from pleural mesotheliomas (rarely or weakly CEA+).