BMPR2 and pulmonary arterial hypertension: Pathogenic gene variants in BMPR2 are the most common genetic risk factor for PAH, but have been associated with only 15% of patients with the non-familial form of the disease16,17, suggesting that variants in non-coding DNA regions might contribute to a reduction in BMPR2 levels or in downstream effectors of BMPR2 mediated gene regulation in patients with PAH.