Most current studies have focused on the regulation of the TGF-β/Smad2/3 signalling pathway (Liu et al. 2024), the reduction of BMPs/BMPR II signaling plays a crucial role in the development of IPF (Ye et al. 2024), but the classical pathway mediated by Smad1/5/8 is key to the antifibrotic effects of BMP. The gene discussed is SMAD1; the disease is idiopathic pulmonary fibrosis.