The top ten ranked genes were BMPR1A, TGFBR1, TGFBR2, ANGPT1, PDGFRA, PDGFRB, TGFBR3, SCN5A, SERPINE1, and TGFB1. Not surprisingly, the majority of these top ranked genes are involved in key pathways of PAH, such as the “TGF-beta signaling pathway.” Although these candidate genes have been demonstrated to have abnormal gene expression or other functional relevance to PAH, most of them have not been reported as having detectable genetic variants in PAH patients. This evidence concerns the gene SERPINE1 and pulmonary arterial hypertension.