Phosphodiesterase-5 (PDE5) is tadalafil, sildenafil, as well as soluble guanylate cyclase (sGC) stimulants, as it has long-term survival rates and can be combined with other agents for better outcomes, so they have been authorized for use in treating PAH since the 1990s (riociguat). This evidence concerns the gene PDE5A and pulmonary arterial hypertension.