HLA-DRB1 and systemic lupus erythematosus: Significantly different carrier frequencies of certain DRB1 alleles were found to be associated with SLE as follows: increased DRB1*15:01 (P = 5.48×10−10, corrected P (Pc) = 1.59×10−8, odds ratio [OR] 2.17, 95% confidence interval [CI] 1.69–2.79), decreased DRB1*13:02 (P = 7.17×10−5, Pc = 0.0020, OR 0.46, 95% CI 0.34–0.63) and decreased DRB1*14:03 (P = 0.0010, Pc = 0.0272, OR 0.34, 95% CI 0.18–0.63).