Anti-CEACAM5 antibodies are used in the immunodetection of the protein CEA cell adhesion molecule 5. In humans, the canonical protein has a reported length of 702 amino acid residues and a mass of 76.8 kDa. Its subcellular localization is in the cell membrane. Up to 2 different isoforms have been reported for this protein. It is reported to be expressed in columnar epithelial and goblet cells of the colon. A member of the CEA protein family, CEACAM5 is known to be involved with the apoptotic pathway and cell adhesion. Post-translational modifications have been described, including glycosylation. Synonyms for this target antigen include CD66e and CEA. CEACAM5 gene orthologs have been reported in the mouse and chimpanzee species.