After analyzing glycolysis enzymes: phosphofrutokinase-1(PFK-1, also known as PFKM), pyruvate kinase muscle isozyme (PKM), lactate dehydrogenase A (LDHA), and hexokinase 2 (HK2) in response to hypoxia, results showed that glycolysis was significantly upregulated in cancer cells, especially in the highly malignant cells (Fig. 2b–d,g). This evidence concerns the gene HK2 and cancer.