The physiological importance of SOD2 is high-lighted by the finding that in contrast to other SOD isoforms, the deficiency of SOD2 causes early neonatal death in gene knockout mice [19] and endothelial dysfunction in carotid artery of proatherogenic apolipoprotein E (ApoE)-deficient mice [11,20]. The gene discussed is SOD2; the disease is endothelial dysfunction.