HK2 and hepatocellular carcinoma: Glucose transporter protein type 1 (GLUT1) and the three rate-limiting enzymes in the glycolytic process, including hexokinase 2 (HK2), lactate dehydrogenase (LDHA), and phosphoglycerate kinase 1 (PGK1), play important roles in aerobic glycolysis of HCC and can be regulated by many mechanisms, such as the signaling pathways and long non-coding RNAs (lncRNAs) [8–14].