The majority of the heritable forms of PAH are caused by mutations in the type II receptor of the BMPR2 gene, which belongs to the transforming growth factor beta (TGF-β) receptor signaling family; of those carriers, 20% are at risk of developing PAH [9] over their lifetime, suggesting that a combination of inherited predisposition and environmental and epigenetic modifiers are required to elicit the phenotype. Here, BMPR2 is linked to pulmonary arterial hypertension.