NOX4 and neoplasm: In stellate cells, NOX4 is required for TGF-β-induced myofibroblast activation, contributing to the development of liver fibrosis,26 which attracted interest in the development of NOX inhibitors that could be used in the clinic to ameliorate this disease.27 However, in hepatocytes and liver tumour cells, NOX4 mediates TGF-β-induced mitochondrial-mediated apoptosis, through modulation of the expression of the pro-apoptotic genes BIM and BMF,28 which contributes to its well-known tumour suppressor effects.