EDN1 and pulmonary fibrosis: The prediction that TGFβ induces fibrotic signaling pathways such as those involved in idiopathic pulmonary fibrosis and hepatic fibrosis is based on upregulation of genes such as connective tissue growth factor (CCN2), a known regulator of fibrosis [34,35]; endothelin 1 (EDN1), a potent vasoconstrictor with pro-fibrotic effects [36,37]; and MET protooncogene, which is involved in cell proliferation, migration, and tissue repair [38].