We confirmed the reduced protein expression of BMPR2 and its downstream signaling component, pSmad 1/5/8, in both hPAH and iPAH, but surprisingly, both the MCT and SuHx rats model for experimentally induced PAH showed an increased vascular expression of BMPR2 in the end stage disease. The gene discussed is BMPR2; the disease is pulmonary arterial hypertension.