TLR3 and pulmonary arterial hypertension: Furthermore, the TLR3 agonist polyinosinic/polycytidylic acid [Poly(I: C)] enhances the binding of IRF3 to the bone morphogenetic protein receptor II (BMPR2) promoter, thereby inhibiting clonal proliferation of endothelial cells and alleviating pulmonary arterial hypertension (PAH) caused by vascular remodeling (36).