A statistically significant upregulation of NOX4 in patient-matched tumor samples compared with normal samples was found in HNSCC, EAC, and colon adenocarcinoma (COAD) (Figure 3A), and similar upregulation was also found in breast carcinoma (BRCA) and lung adenocarcinoma (LUAD; paired two-sided t test P < .001 for all). Here, NOX4 is linked to head and neck squamous cell carcinoma.