Decreased levels of both prostacyclin and nitric oxide have been found in patients with IPAH, and exogenous administration of them are validated therapies for patients with the disease.[2] Thus, a decrease in intravascular ATP concentration through increased microparticle ATPase activity may contribute to the increased pulmonary vascular resistance measured in patients with IPAH. This evidence concerns the gene DNAH8 and idiopathic pulmonary arterial hypertension.