SOD2 and type 2 diabetes mellitus: Glutathione-S-transferase M1 (GSM1) is associated with T2D97 and SCZ.98 As oxidative stress is present in aging disorders of the general population at a higher prevalence than the SCZ–T2D association, we do not think that oxidative stress is the cause of SCZ–T2D comorbidity, but that a GSM1 or SOD2 variation may predispose to inability to counter-effect oxidative stress triggered by other factors.