In this study, we have used human exosomes in immunocompetent mice. It was already published that exosomes derived from human progenitor cells can induce therapeutic effects in immunocompetent small35 and large36 animal models. Nonetheless, we cannot discount the possibility that an immune response could have reduced the therapeutic efficacy of the exosomes. In line with this possibility, the positive impact of PF exosomes on blood flow recovery was not sustained over time. On the other hand, exosomes have been suggested to be able to modulate immunity.37 Given the increasingly recognized importance of the crosstalk between the immune and cardiovascular systems in health and disease, we would not exclude that exosomes could influence cardiovascular responses partly by modulating the immune system.