CD79A and rheumatoid arthritis: Another locus on chr.5q11.2 (rs6859219, Beta = 0.07, P = 1.41 × 10−20) encoding ANKRD55 (closest gene) and IL6ST has previously been associated with IgA levels20, IgG glycosylation50 and increased risk of multiple sclerosis, rheumatoid arthritis, and Crohn’s disease (Fig. 1c, Supplementary Data 2).