EDN1 and idiopathic pulmonary fibrosis: As for the therapeutic implication of ET-1 for pleural fibrosis, previous reports have demonstrated that ET receptor antagonist treatment efficiently attenuated ET-1–mediated alveolar EMT in vitro [5,6], mitigated bleomycin-induced lung fibrosis in vivo [27], and displayed a favorable trend to improve progression free survival of histology–proven IPF patients [28,29].