The present study demonstrates that both IFN-γ and PFD attenuate the activation of NHLFs and IPF fibroblasts at several regulatory levels, including the inhibition of lung fibroblast proliferation, migration, differentiation to myofibroblasts and collagen secretion, after TGF-β1 and PDGF-BB stimulation. This evidence concerns the gene IFNG and idiopathic interstitial pneumonia.