The human CEACAM family. Schematic depiction of the twelve members of the human carcinoembryonic antigen-related cell adhesion molecules. The red spheres indicate IgV-like domains, the blue spheres indicate IgC2-like domains, which are stabilized by disulfide bonds (S-S). The green spirals indicate transmembrane helices. GPI-anchors are depicted in the form of a green arrow ending in the lipid bilayer. CEACAM20 encodes only a partial IgV-like domain (N*). Graph modified from http://www.carcinoembryonic-antigen.de/.