TGFB1 and renal fibrosis: TGF-β1 is predominantly expressed in renal tubular epithelial cells, increasing extracellular matrix expression by stimulating myofibroblasts, enhancing adhesion between cells and matrix, and promoting the aggregation of the extracellular matrix in the renal interstitium, which is an important cytokine leading to renal fibrosis (Yang et al., 2023).