HLA-DRB1 and rheumatoid arthritis: In patients as compared with controls, HLA-DRB1*03-DQB1*03 [2.8% vs -%, P = 0.00003, OR (95% CI) = 2.54 (2.20-2.93)], HLA-DRB1*04-DQB1*03 [3.2% vs 0.5%, P = 0.00014, OR (95% CI) = 10.85 (2.42-48.65)], HLA-DRB1*13-DQB1*02 [1.4% vs -%, P = 0.004, OR (95% CI) = 2.46 (2.14-2.83)], and HLA-DRB1*13-DQB1*03 [5.6% vs 0.2%, P = 3.79x10-8, OR (95% CI) = 41.11 (5.48-308.46)] were associated with RA risk, each of which remained significant after correction of multiple comparisons (Pc = 0.0003, Pc = 0.0001, Pc = 0.032, and Pc = 3.3x10-9, respectively).