TGFB1 and pulmonary arterial hypertension: A major paradigm shift occurred in 2024 when the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) approved the first biologic therapy specifically developed for PAH: sotatercept, a recombinant homodimeric fusion protein of the human activin receptor type IIA-Fc (ActRIIA-Fc), acts as a ligand trap for members of the TGF-β superfamily, effectively removing excess activin-A and other ligands that bind to ActRIIA.