Regarding heterogeneity and sensitivity, Cochran’s Q-test (PQ > 0.05) and MR-Egger regression indicated no heterogeneity in the causal effect between IL-17A/ IL-17 RA, IL-17C/ IL-17 RC, IL-17D/IL-17RD, and RA. The gene discussed is IL17A; the disease is rheumatoid arthritis.