COL4A1 and renal fibrosis: As TGF-β is responsible for the expression of collagen-related genes [25], we also did not see any upregulation of col1a1a, col4a1 and fn1a, and even observed a strong downregulation in case of col1a1a. In contrast, vim, commonly used as a marker of epithelial to mesenchymal transition (EMT) resulting in renal fibrosis [26], as well as mmp9, a matrix metalloproteinase that is an inducer of EMT [27,28] were clearly upregulated.