Furthermore, Loch et al found that MnSOD+/− mice displayed a decrease in fraction shortening and ejection fraction and an increase in left ventricular internal diameter in systole, and developed heart hypertrophy with accompanying fibrosis and necrosis, demonstrating that lifelong reduction of MnSOD activity has a negative effect on normal heart function (Loch et al., 2009). This evidence concerns the gene SOD2 and cardiac hypertrophy.