Pulmonary artery smooth muscle cells isolated from pulmonary arterial hypertension patients exhibit an increased amount and activation of poly (ADP-ribose) polymerase 1, which promotes the survival and proliferation of pulmonary artery smooth muscle cells40, while endothelial cells undergo apoptosis and endothelial cell dysfunction, as observed in pulmonary arterial hypertension patients69. The gene discussed is PARP1; the disease is pulmonary arterial hypertension.