Pulmonary arterial hypertension (PAH) is a complex disease of the lungs that includes vascular abnormalities, and it has been found that in 70-80% of the heritable PAH cases, the BMPRII (which is also bound by BMP-9) is mutated [97], implying that the BMP-pathway is relevant for the pathogenesis of this disease. The gene discussed is GDF2; the disease is pulmonary arterial hypertension.