The conversion of glucose to lactate in the absence of oxygen has been termed anaerobic glycolysis.
Glycolysis provides 2 moles of ATP per mole of glucose.
The enzyme responsible for net ATP production is pyruvate kinase.
The hydrogen that is produced by the glycolytic glyceraldehyde 3-P dehydrogenase reaction is excreted as lactate.
All tumor cells possess large amounts of glycolytic enzymes.
Therefore, at low oxygen pressure energy production is possible via glycolysis.