HK2 and neoplasm: Indeed, HIF-1 target genes include genes coding glycolytic receptors and enzymes, such us the glucose transporter GLUT1, the hexokinase II (HKII), the lactate dehydrogenase A (LDHA), and the pyruvate dehydrogenase kinase 1 (PDK1) [84, 107–109], necessary to switch the tumor cells from oxidative to anaerobic glycolysis in order to adapt to tumor hypoxic condition [110, 111] (Fig. 1B).