NOX4 and neoplasm: Precious study has revealed that NOX4 expression in RCC tissues mediates the expression and activity of hypoxia-inducible factor 2α (HIF-2α), a crucial transcriptional factor of tumor glycolysis and various malignant behavior, to support renal tumorigenesis (Maranchie and Zhan, 2005; Hoefflin et al., 2020; Singhal et al., 2021).