GPR18 and pulmonary arterial hypertension: Pulmonary arterial hypertension can be elicited by a multitude of pathophysiological alterations [40], and GPR18 agonists may become an additional strategy for its treatment, thereby adding to the armamentarium of drugs, including prostacyclin analogues, endothelin receptor antagonists, phosphodiesterase 5 inhibitors, and soluble guanylate cyclase stimulators [41].