HIF1A and myocardial infarction: However, in a rat model of myocardial infarction it has been shown that exosomes derived from human umbilical cord MSCs (UC-MSCs) that overexpress hypoxia-inducible factor 1 (HIF-1α) significantly reduced cardiomyocyte apoptosis, enhanced angiogenesis, reduced scar size, and improved cardiac function [57].