Specifically, for T2D, both ELISA (SMD = 0.27, 95% CI: −1.82 to 2.35, n = 5) and HPLC + ICP-MS (SMD = −1.42, 95% CI: −3.07 to 0.24, n = 2) did not find any significant differences in the SELENOP levels between the patients and controls (Supplementary Figure S7). The gene discussed is SELENOP; the disease is type 2 diabetes mellitus.