TGFB1 and pulmonary arterial hypertension: Different from all previous therapeutic drugs for PAH, Sotatercept is an activin signal inhibitor and a First-in-class activin receptor IIA-Fc (ActRIIA Fc) fusion protein, which can selectively bind TGF-β family ligands, restore the balance between pro-proliferation and anti-proliferation signal pathways related to pulmonary artery wall and right ventricular remodeling, and play the role of inhibiting cell proliferation, reversing vascular remodeling and smoothing blood vessels (102).