Gräf et al. [24] reported rare heterozygous BMPR2 mutations in 160 of 1048 PAH cases (15.3%); the frequency of BMPR2 mutations in FPAH, IPAH and anorexigen-exposed PAH were 75.9%, 12.2% and 8.3%, respectively. Here, BMPR2 is linked to heritable pulmonary arterial hypertension.