HK2 and neoplasm: HK2, a predominant isoform of hexokinase, catalyzes the rate-limiting step of phosphorylation of glucose to generate glucose 6-phosphate during glycolysis [43], as shown in the schematic illustration of glycolysis in Fig. 5B. The increased aerobic glycolysis, or the Warburg effect, is another hallmark of cancer [44], and the glycolysis level of tumor cells largely determines their proliferation ability.