NOX4 and cancer: Increased oxidative stress during EMT occurred in tandem with the overexpression of oxidative stress‐related biomarkers, such as nuclear respiratory factor 2 (NRF2), nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) and glutathione peroxidase 1 (GPX1), in wild‐type and YWHAG‐knockdown cancer cells during EMT compared with untreated cells (Figure 3C–E; Figure S9C–E, Supporting Information).