In vivo, adeno-associated virus AAV9-mediated IGF2BP3 overexpression in the left ventricular myocardium of P1 mice, followed by MI surgery, increases proliferative CMs and results in improved cardiac hypertrophy, reduced myocardial infarction size, decreased myocardial fibrosis, and preserved left ventricular ejection fraction. Here, IGF2BP3 is linked to myocardial infarction.