NOX4 and glioblastoma: Several studies demonstrated that NADPH oxidase subunit 4 (Nox4) is expressed in several human tumors, such as glioblastoma [5], hepatocellular carcinoma [6], breast cancer [7], thyroid cancer [8], and melanoma [9], and is involved in cellular senescence, resistance to apoptosis, tumorigenic transformation, cell proliferation, cell survival, and chemotherapy resistance.