For patients using JAK inhibitors vs TNF antagonists, there was no significant difference in risk of serious infections (IR, 3.79 [95% CI, 2.85-5.05] vs 3.03 [2.32-3.95] per 100 person-years; pooled HR, 1.05 [95% CI, 0.97-1.13]), malignant neoplasms (IR, 1.00 [0.77-1.31] vs 0.94 [0.72-1.22] per 100 person-years; pooled HR, 1.02 [0.90-1.16]), or MACEs (IR, 0.72 [0.56-0.92] vs 0.66 [0.49-0.89] per 100 person-years; pooled HR, 0.91 [0.80-1.04]), with minimal to moderate heterogeneity. This evidence concerns the gene TNF and infection.