NDUFS1 and Myocardial fibrosis: One study revealed that high levels of oxidative stress in the skin fibroblasts of patients with NDUFS1 mutations were accompanied by decreased complex I activity, decreased oxygen consumption, and increased glycolysis [19], and reduced expression of NDUFS1 in the myocardium may be an important cause of myocardial dysfunction and myocardial fibrosis [20].