Glucose transporters and enzymes with a pivotal role in glycolysis, such as hexokinase II (HKII), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), lactate dehydrogenase (LDH), and the isoform M2 of pyruvate kinase (PKM2) are usually upregulated in cancer cells and have been proposed as possible therapeutic targets. This evidence concerns the gene PKM and cancer.