In addition, IVW analyses showed that IL-17C/IL-17RC, and IL-17D/IL-17RD demonstrated no causal impact on RA (IL-17C(OR = 1.007, 95%CI = 0.890–1.139, p.adj = 0.152), IL-17RC(OR = 1.006, 95%CI = 0.904–1.119, p.adj = 0.152), IL-17D(OR = 0.979, 95%CI = 0.843–1.137, p.adj = 0.130), IL-17RD(OR = 0.983, 95%CI = 0.876–1.104, p.adj = 0.129)), and these results were confirmed by the weighted-median and MR-Egger analyses. Here, IL17C is linked to rheumatoid arthritis.