HK2 and carcinoma of esophagus: Hensley et al. [41] have reported that curcumin, a polyphenol extracted from Curcuma longa and being tested for the prevention and treatment of oral, head and neck, lung, and pancreas cancer, as well as osteosarcoma, glioblastoma, and chronic lymphocytic leukemia in clinical trials, decreased glucose transporter 4, hexokinase 2 (HK2), 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3, and pyruvate kinase M2 at the mRNA and protein levels via AMPK-mediated regulation in oesophageal cancer cells [42,43] (Figure 1).