Taken together, these data suggest that in particular, let-7b through its targets ET-1 and TGFBR1, which have previously been implicated in CTEPH pathophysiology, but also other microRNAs, might be involved in the regulation of important pathways affecting the cells in the pulmonary vasculature in a way that ultimately leads to the development of CTEPH. This evidence concerns the gene EDN1 and chronic thromboembolic pulmonary hypertension.