In subsequent functional analysis, we observed increased apoptosis and hyperpermeability in MCTP‐treated rPAECs with Cirp depletion, which was caused by reduced expression of CAV1 or CAVIN1, indicating that CIRP mediates MCT‐induced PAH through regulating the level of CAV1 and CAVIN1 in pulmonary artery endothelium. Here, CIRBP is linked to pulmonary arterial hypertension.