Studies using endothelial specific knockdown of SOX17 show either no pulmonary hypertension or trends toward increases in basal RV systolic pressure and RV hypertrophy compared to wild-type mice but more severe pulmonary hypertension or earlier development of pulmonary hypertension in response to chronic hypoxia or sugen/hypoxia (Su/Hx-PH), suggesting that loss of endothelial SOX17 expression exacerbates pulmonary hypertensive responses (41, 43, 44). This evidence concerns the gene SOX17 and pulmonary arterial hypertension.