In model 4, ISIM and ISSI-2 were further adjusted based on model 3, and statistical significance of the association between SOD activity and MS was attenuated (OR for 1SD increase of SOD = 0.750, 95% CI 0.576-0.978, P = 0.034), suggesting a possible mediating effect of insulin sensitivity and β-cell function on the link between SOD activity and MS. This evidence concerns the gene SOD1 and myeloid sarcoma.