To validate the role of the SIRT1/Nrf2 signaling pathway in mediating the effects of liquiritigenin in bleomycin-induced pulmonary fibrosis, we administered specific inhibitors of SIRT1 (EX527) or Nrf2 (ML385) 3 h before liquiritigenin treatment (Fig. 8A). This evidence concerns the gene SIRT1 and pulmonary fibrosis.