SOD2 and Stroke: Animal studies have shown that higher estrogen levels in females protect against aging by upregulating the expression of antioxidant, longevity-related genes, e.g., selenium-dependent glutathione peroxidase (GPx) and Mn-superoxide dismutase (Mn-SOD) [1], by protecting against stroke-related injury [2], by vasorelaxing effects [3], by direct myocardial protection [4], and by activating the insulin receptor substrate (IRS)-1 signaling pathway [5].