CD1d 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. CD1d is an antigen-presenting protein that binds self and non-self glycolipids and presents them to T-cell receptors on NKT cells. When activated,NKT cells rapidly produce Th1 and Th2 cytokines. The molecular weight of unglycosylated CD1d is 38 kDa,while glycosylated form of CD1d is 48-55 kDa.