More indications for the differential regulation of IgG and IgA glycosylation can be found in literature: in rheumatoid arthritis, the level of galactosylation of IgG decreases dramatically (e.g. [54]–[56]), while N-glycans in the IgA enriched fractions are hardly changed [54], [57]. The gene discussed is CD79A; the disease is rheumatoid arthritis.