EZH2 and myocardial infarction: After 100 μg of MSC-EXO was administered to MI rats via the tail vein for 7 consecutive days, EZH2 expression was reduced, and high mobility group AT-hook 2 (HMGA2) expression was activated to block PI3K/AKT signaling, inhibiting myocardial fibrosis in MI rats (80).