Pyruvate kinase PKM is an isoenzyme of the glycolytic enzyme pyruvate kinase. Depending upon the different metabolic functions of the tissues, different isoenzymes of pyruvate kinase are expressed. The pyruvate kinase isoenzyme type M2(PKM2) is expressed in some differentiated tissues, such as lung, fat tissue, retina, and pancreatic islets, as well as in all cells with a high rate of nucleic acid synthesis, such as normal proliferating cells, embryonic cells, and especially tumor cells. As a glycolytic enzyme that catalyzes the transfer of a phosphoryl group from phosphoenolpyruvate (PEP) to ADP, generating ATP. It stimulates POU5F1-mediated transcriptional activation and Plays a general role in caspase independent cell death of tumor cells. The ratio between the highly active tetrameric form and nearly inactive dimeric form determines whether glucose carbons are channeled to biosynthetic processes or used for glycolytic ATP production. The transition between the 2 forms contributes to the control of glycolysis and is important for tumor cell proliferation and survival. Synonyms: Cytosolic thyroid hormone-binding protein,Opa-interacting protein 3,Pyruvate kinase 2/3,Pyruvate kinase muscle isozyme,Thyroid hormone-binding protein 1,Tumor M2-PK,p58,CTHBP,OIP3,PK2,PK3,TCB,THBP1