NOX4 and cancer: In line with the literature, we found positive transcriptional activity for NOX4 in mSMCCs (Figure 4c), downregulation of c‐MYC (Figure 3a), G1 phase synchronized cancer cells (Figure 4d), and upregulation of the CDK inhibitory genes p15Ink4b and p21Cip1 (Figure 4e,f); the upregulation of hydrogen peroxide‐inducible clone 5 (HIC5) (Figure 4g), a sensor of free radicals and an antagonist of NOX4 (Desai et al., 2014; Wolfgang Doppler, 2019), confirmed the tissue response to NOX4 activation.