STAT3 and idiopathic pulmonary arterial hypertension: Other studies suggest targeting BMPR2 signaling could benefit PH treatment, with BMP9 directly activating the BMPR2 pathway.39,393 Elafin, an endogenous elastase inhibitor augments BMPR2 signaling by enhancing the interaction between BMPR2 and CAV1.394 High inhibin-β-A expression in IPAH patients promotes autocrine ActA secretion, while follistatin stabilizes BMPR2.30 Inhibition of IL-6/STAT3 signaling may enhance BMPR2 expression,68,395.