Our observations are largely consistent with a previous study that showed no differences in RV hypertrophy between AT1R antagonist losartan and vehicle-treated rats with MCT-induced PAH (4); however, in contrast to our findings, they observed RV afterload was reduced in losartan-treated rats with PAH, without affecting RV contractility (4). The gene discussed is AGTR1; the disease is pulmonary arterial hypertension.