Our laboratory has applied knockouts of GPX1 (Gpx1-/-) [8], SOD1 (Sod1-/-), [9] and both (dKO) [10,11] mice and GPX1-overexpressing (Gpx1-OE) mice [12,13] to study the metabolic roles and molecular mechanisms of these redox enzymes in the development of insulin resistance and diabetes. Here, SOD1 is linked to diabetes mellitus.