GAL and rheumatoid arthritis: Similarly, even though IgG2 contained less Fc-galactosylated species than IgG1 in all tested individuals (Fig. 2b), the aGal/Gal ratios correlated between IgG1 and IgG2 relatively well intraindividually (Additional file 1: Figure S3), thus indicating that in patients with RA, both IgG1 and IgG2 contain lower amounts of Fc-galactosylated species than what is normal.