Elevated levels of FGF2 have been detected in bronchoalveolar lavage (BAL) from IPF patients, in lung mast cells of IPF, and in lung macrophages and mast cells of bleomycin-treated mice [86–88].Interestingly, while endogenous FGF2 is essential for the production of fibrosis, it does not participate in TGF-β1-induced fibrotic differentiation [82]. This evidence concerns the gene TGFB1 and idiopathic pulmonary fibrosis.