S100A4 and renal fibrosis: UII can enhance the expression and secretion of TGF-β1 in renal tubular epithelial cells, induce the expression of α-SMA, fibroblast-specific protein 1 (FSP-1), fibronectin and type IV collagen in human renal tubular epithelial cells, and participate in Renal fibrosis process [11–13].