TGFB1 and pulmonary arterial hypertension: Comparative analysis of therapeutic attractiveness of different members of TGF-β superfamily to target hyper-proliferative PAVSMC in human PAH, however, had not been performed, and their relationship with other pro-proliferative pathways, such as platelet-derived growth factor (PDGF) signaling, known PAVSMC mitogen in PAH, remains to be established.