CD1a is a transmembrane glycoproteins， which is structurally related to the major histocompatibility complex （MHC） proteins and form heterodimers with beta-2-microglobulin. CD1a mediates the presentation of primarily lipid and glycolipid antigens of self or microbial origin to T cells. The human genome contains five CD1 family genes organized in a cluster on chromosome 1. The CD1 family members are thought to differ in their cellular localization and specificity for particular lipid ligands. The protein encoded by this gene localizes to the plasma membrane and to recycling vesicles of the early endocytic system. Alternatively spliced transcript variants have been observed， but their biological validity has not been determined.
