PDE5A and pulmonary arterial hypertension: These drugs have been shown to decrease pulmonary vascular resistance and increase exercise capacity for preferable outcomes in PAH patients.21,22 We recently found a novel caNPR2 when we analyzed a family case of overgrowth and bone anomalies.11 Since this caNPR2 mutant may more strongly enhance the synthesis of cGMP than PDE5 inhibitors and a sGC stimulator, we investigated the therapeutic effects and safety of gene therapy using caNPR2 in this study.