CDIP1 and myocardial infarction: Importantly, the present study is the first to reveal a novel mechanism by which exosomal miR-21-5p derived from CTs inhibits CMEC apoptosis via the targeted silencing of the Cdip1 gene under hypoxic and ischemic conditions, and transfection of miR-21-5p decreases the infarct size, improves cardiac function, increases cardiac angiogenesis and improves MI regeneration.