CEA-related cell adhesion molecules (CEACAM) belong to the carcinoembryonic antigen (CEA) family. It consists of seven CEACAM (CEACAM 1, CEACAM 3-CEACAM 8) and 11 pregnancy-specific glyco-protein (PSG 1-PSG 11) members. The CEA family proteins belong to the immunoglobulin (Ig) superfamily and are composed of one Ig variable-like (IgV) and a varying number (0-6) of Ig constant-like (IgC) domains. CEACAM molecules are membrane-bound either via a transmembrane domain or a glycosyl phosphatidyl