IL18 and type 2 diabetes mellitus: For MR analysis, all IVs have to be independent of one another and robustly associated with the phenotype (e.g., high IL-18 levels) but not with the disease (e.g., T2DM) (Figure 1), ensuring that the only way for the IVs to influence the disease is through the phenotype, with maximum avoidance of any possible residual confounding factors.