PKM and cancer: The expression of glycolytic enzymes, including LDHA, HK2, phosphoglycerol kinase 1 (PGK1), and pyruvate kinase isoform M2 (PKM2), as well as glucose and lactate transport proteins, such as GLUT1 and monocarboxylic acid transporter 4 (MCT4), are upregulated to enhance glucose uptake during glycolysis in cancer cells [39, 40].