PPARG and idiopathic pulmonary fibrosis: Curiously, it has been reported that the first-line antidiabetic drug metformin exerts potent antifibrotic effects by modulating metabolic pathways, activating PPAR-γ signalling, inhibiting TGF-β, suppressing collagen formation and inducing lipogenic differentiation in lung fibroblasts derived from IPF patients [79], but unfortunately it does not have clinically relevant outcomes in patients [80].