Later, Huang et al. (75) observed increased expression of ET-1 and ET-1 receptors (ETRs), and activation of urvivin-Akt, urvivin-ERK1/2, and phos-pho-mTOR pathways in the pulmonary arteries and small arteries of PAH-CHD patients. This evidence concerns the gene EDN1 and pulmonary arterial hypertension.