TGFB1 and pulmonary arterial hypertension: IGFBP-7 promotes vascular remodeling via modulation of TGF-β/BMP pathways and prostacyclin production. It is elevated in PAH (especially hepatopulmonary syndrome-associated PAH) and correlates with right heart dysfunction and poor prognosis. and It is a strong candidate biomarker and potential therapeutic target.a