Delivery of engineered Tβ4-exosome (Tβ4-EXO, thymosin β4 is a keypro-angiogenic factor) in mice stimulates the formation of collateral circulationafter myocardial infarction and enhances the angiogenesis of coronary arteryendothelial cells via the miRNA-17-5p/PHD3/HIF-1α pathway [86].Tβ4-exosome induces the expression of exosomal-miRNA-17-5p, whichinhibits ubiquitination of HIF-1α by targeting PHD3. Here, HIF1A is linked to myocardial infarction.