HLA-DRB1 and rheumatoid arthritis: Three of the 11 independent amino acid variations, HLA-DRB1 residue 67 and 71, HLA-DQB1 residue 55 are associated with type 1 diabetes, multiple sclerosis, hypothyroidism, rheumatoid arthritis, and inflammatory polyarthritis according to PheWAS database (41, 42).