Our study found that the expressions of SIRT1 and GPX4 were continuously decreased by the elevated concentrations of TGF-β or Erastin in tubular cells and in renal fibrosis model mice, which were blocked by Fer-1 (Figure 8), indicating that the downregulations of SIRT1 and GPX4 were associated with the trigger of ferroptosis in renal fibrosis. Here, GPX4 is linked to renal fibrosis.