IL1B and rheumatoid arthritis: Furthermore, genetically predicted higher levels of IL1-RA were strongly associated with the positive control outcomes, including lower levels of CRP (β = -0.18, 95% confidence interval [CI] -0.22, -0.15, P = 2.54×10-24) and a decreased risk of rheumatoid arthritis (odds ratio = 0.85, 95% CI 0.78-0.93, P = 2.37×10-4).