CD1B is a member of the CD1 family of transmembrane glycoproteins, which are structurally related to the major histocompatibility complex (MHC) proteins and form heterodimers with beta-2-microglobulin. This protein contains 1 Ig-like (immunoglobulin-like) domain. CD1B is antigen-presenting protein that binds self and nonself lipid and glycolipid antigens and presents them to T-cell receptors on natural killer T-cells.