Although NOX2, also termed gp91phox, is mainly expressed in phagocytes, the upregulation of this NOX isoform and EMT were inhibited in TGF-β1-knockout cells, suggesting that TGF-β1 is required for NOX2 activation during renal fibrosis and in vascular endothelial cells [21,22]. This evidence concerns the gene CYBB and renal fibrosis.