IL6 and rheumatoid arthritis: By ethnicity, the IL-6-174C allelic, homozygous, and dominant models are significantly associated with 4.55-fold (95% CI: 1.62–12.75; P = 0.003), 1.84-fold (95% CI: 1.13–2.99; P = 0.014), and 4.69-fold (95% CI: 1.68–13.14; P = 0.003) increased risk of RA in Asian populations, respectively, with high heterogeneity for C allelic (I2 = 90.3%), dominant model (I2 = 89.1%), and low heterogeneity for homozygous model (I2 = 17.2%).