The statistical significance of psoriasis association between the TNF inhibitor monotherapy cohorts and methotrexate cohort was calculated at 95% CI level: certolizumab pegol ROR 16.94 and 95% CI [7.86, 36.50], adalimumab 10.29 [4.79, 22.12], golimumab 6.09 [2.57, 14.42], infliximab 4.56 [1.99, 10.41], and etanercept 2.55 [1.20, 5.41]. This evidence concerns the gene TNF and psoriasis.