Anti-Ribophorin II antibodies are used in the immunodetection of the protein encoded by the RPN2 gene. In humans, the canonical protein has a reported length of 631 amino acid residues and a mass of 69.3 kDa. Its subcellular localization is in the ER. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be expressed in all tissues tested. A member of the SWP1 protein family, it is a known subunit of the oligosaccharyl transferase (OST) complex that catalyzes the initial transfer of a defined glycan (Glc(3)Man(9)GlcNAc(2) in eukaryotes) from the lipid carrier dolichol-pyrophosphate to an asparagine residue within an Asn-X-Ser/Thr consensus motif in nascent polypeptide chains, the first step in protein N-glycosylation. Post-translational modifications have been described, including glycosylation. Other names for this target antigen include RPN-II, RPNII, SWP1, dolichyl-diphosphooligosaccharide--protein glycosyltransferase subunit 2, and RIBIIR.