Hexokinase II (also known as HK II) is an enzyme encoded by the HK II gene, located in human chromosome band 2p13. The protein product of the HK II gene is a hexokinase. HK II is a member of the hexokinase family. The hexokinase family consists of four members, that is, HK I, HK II, HK III, and HK IV. HK II phosphorylates a six-carbon sugar called hexose to a hexose phosphate. Aberrant activation of HK II has been linked with a variety of malignancies, participating as the principal functional isoform in multiple cancer cells. It also contributes to aerobic glycolysis, acting as a pivotal player in an emerging hallmark of cancer, the Warburg effect (Hanahan and Weinberg 2011). HK II is proposed to be a metabolic target for cancer therapeutic development.