Component of the ankyrin-1 complex, a multiprotein complex involved in the stability and shape of the erythrocyte membrane (PubMed:35835865). Mediates the primary membrane attachment site for ANK1 when associated with RHAG (PubMed:35835865). May participate in the ammonium and carbon dioxide transport through the heterotrimer form (Probable). . This is the function of ENSG00000188672 (RHCE, Rh blood group CcEe antigens).