In a meta-analysis of randomised studies, exposure to TNF inhibitors was associated with a three-fold increase in the risk of TB reactivation compared with placebo or no treatment (fixed-effects model, OR: 3.5, 95% CI: 1.6–7.9; random-effects model, OR: 3.3, 95% CI: 1.5–7.3) [117]. This evidence concerns the gene TNF and tuberculosis.