The frequencies of presumably Risky (R) HLA-DRB1 alleles (DRB*01, *04, and *10) were 59 of 102 (57.8%), 20 of 60 (33.3%), and 16 of 80 (20%), while the frequencies of presumably protective (P) HLA-DRB1 alleles (DRB*11 and *13) were 17 of 102 (16.7%), 16 of 60 (26.7%), and 34 of 80 (42.5%) in ACPA-positive RA patients, ACPA-negative RA patients, and healthy controls, respectively Table 1. The gene discussed is HLA-DRB1; the disease is rheumatoid arthritis.