During the past few decades, advances in understanding of the pathogenesis of PAH have led to significant progress in PAH-targeted medications, including phosphodiesterase-5 inhibitors (PDE-5i), endothelin receptor antagonists (ERAs), prostacyclin analogues and prostacyclin receptor agonists (PGI2), and soluble guanylate cyclase stimulators (sGCs). This evidence concerns the gene PTGIR and pulmonary arterial hypertension.