FNDC5 and Myocardial fibrosis: According to recent studies, serum irisin, the expression of FNDC5/irisin genes and proteins, as well as the downstream AMPK activity in cardiomyocytes were significantly increased after 8 weeks of aerobic exercise in rats with DCM, which were closely related to the decreased mRNA and protein expression of mitochondrial fission proteins, such as Drp1, fission-1 protein (Fis1) and mitochondrial fission factor (MFF) in cardiomyocytes, and the amelioration of myocardial fibrosis [62].