BMPR2 and pulmonary arterial hypertension: With the progress in genetic approaches, a wide range of defective gene expression profiles have been identified, which are highly related to the pathogenesis of multiple respiratory diseases, such as bone morphogenetic protein type 2 receptor (BMPR2) in pulmonary arterial hypertension (PAH) and cystic fibrosis transmembrane conductance regulator (CFTR) in cystic fibrosis (CF) [4,5].