TGFB1 and renal fibrosis: Extensive tubulointerstitial fibrosis, assessed using Masson’s trichrome (MT) staining, was observed in the AA group (Figure 2B), as well as with upregulation of the mRNA levels of renal fibrosis-related genes, collagen I and III, and transforming growth factor (TGF)-β (Figure 2C–E).