HK2 and central nervous system cancer: Several important glycolytic enzymes (regulators) including hexokinase 2 (HK2)8,9,12, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3)8,13, pyruvate kinase M2 (PKM2)8,9,14, and lactate dehydrogenase 5 (LDH5)8,15 have been revealed to be upregulated in glioma cells and are preferentially used by cancer cells8.