In contrast, exercise has been found to increase Fibroblast growth factor 21 (FGF21) protein expression, inactivate the TGF-β1-Smad2/3-MMP2/9 signaling pathway, reduce myocardial fibrosis, oxidative stress and apoptosis, and finally improve cardiac function in MI mice230. Here, FGF21 is linked to Myocardial fibrosis.