The MSC-derived exosomes inhibited vascular remodeling and consequent pulmonary hypertension through suppression of the hypoxic activation of STAT3 and upregulation of the miR-17 superfamily of miRNA clusters, whereas it increased lung levels of miR-204, a known key miRNA that is decreased in human pulmonary hypertension. This evidence concerns the gene STAT3 and pulmonary hypertension.