In mice, the overexpression of major antioxidant enzymes such as copper-zinc superoxide dismutase (CuZnSOD or SOD1), catalase, or manganese superoxide dismutase (MnSOD) did not increase longevity [183], while deletion of mitochondrial matrix SOD increased mtDNA damage and cancer incidence but did not accelerate ageing [184,185]. Here, SOD2 is linked to cancer.