IL9 and polyp of gallbladder: We identified a credible correlation between circulating interleukin-9 (IL-9) levels and gallbladder polyp risk in univariable MR analysis (IVW—OR: 0.523, 95%CI: 0.345–0.794, p = 0.0007; WM—OR: 0.552, 95%CI: 0.327–0.932, p = 0.026; MR Egger—OR: 0.470, 95%CI: 0.152–1.456, p = 0.252).