TGFB1 and pulmonary fibrosis: TGF-β1 promotes collagen synthesis through the following mechanisms, as determined by an examination of its mechanistic contribution to chronic kidney diseases and idiopathic pulmonary fibrosis: (i) activation of downstream signalling pathways, including the TGF-β1/Smad pathway; (ii) increased de novo synthesis of serine; and (iii) increased expression of protease inhibitors (Meng et al. 2016; Nigdelioglu et al. 2016).