Anti-R2 antibodies enable researchers to detect and measure the R2 antigen in biological samples. This target is a reported synonym of the CD1E gene, which encodes CD1e molecule. This protein is known to function in adaptive immune responses, among other biological roles. The human version of R2 has a canonical amino acid length of 388 residues and a protein mass of 43.6 kilodaltons, although 13 isoforms have been identified. It is reported to be localized in the Golgi of cells.