Predicted to enable peptide antigen binding activity and signaling receptor binding activity. Predicted to be involved in several processes, including antigen processing and presentation of endogenous peptide antigen via MHC class I via ER pathway, TAP-independent; antigen processing and presentation of endogenous peptide antigen via MHC class Ib; and positive regulation of T cell mediated cytotoxicity. Predicted to be located in lumenal side of endoplasmic reticulum membrane and phagocytic vesicle membrane. Predicted to be active in external side of plasma membrane and extracellular space; PARTICIPATES IN allograft rejection pathway; antigen processing and presentation pathway; autoimmune thyroiditis pathway; INTERACTS WITH 2,2',4,4'-Tetrabromodiphenyl ether; 2,3,7,8-tetrachlorodibenzodioxine; 3,3',4,4',5-pentachlorobiphenyl.