There is a large cohort of data implicating the BMP pathway in the etiology of PAH as heterozygous mutations within the gene encoding bone morphogenetic protein type II receptor (BMPR2) have been found in ~70 % of FPAH [3, 4] and ~26 % of IPAH cases [6]. This evidence concerns the gene BMPR2 and heritable pulmonary arterial hypertension.