HLA-DRB1 and rheumatoid arthritis: Furthermore, we observed the association between HLA-DRB1 Asn120 and risk of ACPA-positive RA in the Chinese ethnic group; however, the signal was below the suggested PGWAS threshold (OR = 3.05, 95% CI = 2.03–4.58, PGWAS = 8.43 × 10−08).