FNDC5 and myocardial infarction: Further, treatment of in the MI model with irisin (intraperitoneal injection or extracellular incubation) significantly reduces the level of cardiomyocyte apoptosis and myocardial infarct size, as well as significantly improves mitochondrial function, thus promoting recovery of ventricular function (Zhao et al., 2016; Wang et al., 2017; Wang et al., 2018; Li et al., 2019; Liao et al., 2019; Zhao et al., 2019; Deng et al., 2020; Fan et al., 2020; Ouyang et al., 2020; Xin and Lu, 2020).