HLA-DRB1 allele/genotype frequencies were significantly different between ACPA-positive RA patients, ACPA-negative RA patients, and healthy controls (P=0.00), where R allele was weakly correlated with ACPA positivity (τ=0.38, P=0.00) and P allele was weakly correlated with healthy status (τ=0.33, P=0.00). Here, PRTN3 is linked to rheumatoid arthritis.