In this study, we uncover that exosomes produced by human Tohoku Hospital Pediatrics-1 (THP-1) macrophages cultured with the cytokine interleukin-4 (THP1-IL4-exo) reverse cardiac functional decline in mice that developed MI in response to diet-induced occlusive coronary atherosclerosis. This evidence concerns the gene IL4 and myocardial infarction.