ITSN1 and pulmonary arterial hypertension: The authors thank Drs. Serpil Erzurum and Suzy Comhair (Lerner Research Institute, Cleveland Clinic) for providing the pulmonary artery endothelial cells isolated from PAH patients and Dr. Melanie Pritchard, School of Biomedical Sciences, Monash University, Clayton, Australia for providing the ITSN heterozygous knockout mice.