This showed that the level of NOX4 expression accounted for a statistically significant proportion of the variability of these gene signatures in HNSCC, EAC, COAD, rectal adenocarcinoma (READ), invasive breast cancer, LUAD, and pancreatic ductal adenocarcinoma (PDAC) (r = 0.65–0.91, r2 = 0.418–0.833, adj. Here, NOX4 is linked to invasive breast carcinoma.