CASP3 and myocardial infarction: This finding suggests that exosomal miR-21-5p from CTs is a good in vivo regulator that decreases the expression of the Cdip1 gene and the activity of caspase-3, a key apoptotic player, and silencing of the Cdip1 gene via exosomal miR-21-5p may be a potential strategy to improve the proapoptotic microenvironment of the ischemic myocardium and subsequently to facilitate cardiac angiogenesis and regeneration following MI by promoting the survival of transplanted cells and resident cells (such as CMECs).