 Pyruvate kinase catalyzes the last step within the glycolytic sequence, the dephosphorylation of phosphoenolpyruvate to pyruvate and is responsible for net energy production within the glycolytic pathway.Depending upon the different metabolic functions of the tissues, different isoenzymes of pyruvate kinase are expressed.M2-PK (PKM2) is the predominant pyruvate kinase isoform in proliferating cells, such as fibroblasts, embryonic cells and adult stem cells and most human tissue, including lung, bladder, kidney and thymus; M2-PK is upgregulated in many human tumors.