HIF1A and neoplasm: Stabilized heat shock protein 90 (HSP90) maintains hypoxia-inducible factor 1-alpha (HIF1α) protein levels, which in turn transcriptionally upregulates the glycolytic enzymes enolase 2 (ENO2), enolase 3 (ENO3), aldolase c (ALDOC), and acetyl-CoA synthetase 2 (ACSS2) to enhance aerobic glycolysis, while direct stabilization of ENO1 by USP21 further amplifies glycolytic flux and fuels tumor cell proliferation (Figure 8).