TGFB1 and idiopathic pulmonary fibrosis: Along this line, it is interesting to mention that an excessive expression of TGF‐β is present in the lungs of IPF patients and that an excessive signalling through the TGF‐β/SMAD pathway, which leads to an increased formation of collagen and other extracellular matrix components in fibroblast or smooth muscle cells, seems thus contributing to the pathogenesis of lung fibrosis 12, 13, 14.