SMAD3 and idiopathic pulmonary fibrosis: To elucidate the molecular mechanisms underlying the observed phenoytypic differences between NFC- and IPF-derived HLMFs we investigated the basal Smad2/3 content as Smad2/3 signalling is key for myofibroblast differentiation and αSMA gene transcription RT-PCR results confirmed that both Smad2 and Smad3 mRNA were significantly upregulated in IPF-derived HLMFs compared to NFC-derived cells, P = 0.0286 and P = 0.0286 respectively, Mann Whitney (Figure 3A and B).