All other exposures (i.e., IL-1β, IL-4, IL-5, IL-6, IL-18, IL-13, TNF-α, MPO, and blood MPO-DNA complexes) showed no statistically significant causal associations with RA (all IVW P > .05; Figs. S1 and S2, Supplemental Digital Content, https://links.lww.com/MD/Q426). The gene discussed is MPO; the disease is rheumatoid arthritis.