There is increasing evidence showing that dysregulation of exosomal miRNAs occurs in various pathophysiological processes including atherosclerosis, acute coronary syndrome, heart failure, myocardial ischemia–reperfusion injury, and pulmonary hypertension [12, [47]. In these studies, miRNA-205 was demonstrated to be involved in the induction of inflammation and atherosclerosis in vascular endothelial cells by targeting the tissue inhibitor of metalloproteinase-3, which interferes with miRNA-205 expression and thus plays a protective role in vascular endothelial cells [18]. Here, TIMP3 is linked to pulmonary hypertension.