Carcinoembryonic Antigen-Related Cell Adhesion Molecule 3 (CEACAM3) belongs to the immunoglobulin superfamily and CEA family. CEACAM3 was originally described in bile ducts of liver as biliary glycoprotein. Subsequently, it was found to be a cell-cell adhesion molecule detected on leukocytes, epithelia, and endothelia. CEACAM3 mediates cell adhesion via homophilic as well as heterophilic binding to other proteins of the subgroup. In addition, it is associated with the differentiation and arrangement of tissue three-dimensional structure, angiogenesis, apoptosis, tumor suppression, metastasis, and the modulation of innate and adaptive immune responses.