SMAD7 and idiopathic pulmonary fibrosis: In particular, miR21 is upregulated in both IPF and lung cancer: it shows profibrotic activity, promoting TGF beta signaling through downregulation of Smad7, a negative regulator of TGF-beta, in human IPF and in murine bleomycin-induced fibrosis [74,75], and acts as an oncogene in NSCLC, where it represents an independent negative prognostic factor [76].