CD1B belongs to CD1 family of transmembrane glycoproteins, which are structurally associated with the MHC proteins and form heterodimers with the beta-2-microglobulin. CD1B includes one Ig-like domain. CD1B is an antigen-presenting protein which connects self and nonself lipid and glycolipid antigens and displays them to T-cell receptors on natural killer T-cells.