SOD2 and cardiomyopathy: Moreover, mice deficient in SOD2 die of cardiomyopathy within 10 days of birth, whereas heterozygous SOD2(+/−) mice show ultrastructural damage of the myocardium and mitochondria, associated to an increased oxidative stress (nitrotyrosine formation and lipid peroxidation) as well as an activation of apoptotic signaling pathways in the heart [10].