Considering that overexpression of let-7i-5p miRNA can inhibit NF-κB activation, mitochondrial dysfunction and apoptosis, as previously demonstrated in a cell model of myocardial ischemia in cardiomyocytes [57], we conjecture that the therapeutic effects of exosomes observed in this study may very likely be mediated by let-7i-5p miRNA. The gene discussed is NFKB1; the disease is myocardial ischemia.