TGFB1 and pulmonary fibrosis: In the light of our in vitro results regarding PRRX1 role in the control of fibroblast proliferation and TGF-β1 responsiveness, we investigated whether alteration in PRRX1 expression may also contribute to fibrogenesis in the bleomycin-induced model of lung fibrosis (single intratracheal instillation Moshai et al., 2014).