GJA1 and pulmonary arterial hypertension: It would be interesting if future studies assess whether NO production in response to agonists, such as ACh, is similarly affected in the Cx43+/− mice and also investigate the link between Cx43 expression and function and NO production in pulmonary vessels more fully, especially since drugs augmenting NO-mediated vasodilation such as sildenafil are widely used to treat PAH patients.