Pyruvate kinase isoform M2 (PKM2) is a member of the pyruvate kinase (PK) family, a pivotal glycolytic enzyme that is consistently changed during tumorigenesis. PKM2 is expressed in some differentiated tissues, such as lung, fat tissue, retina, and pancreatic islets. As the rate-controlling enzyme in glycolysis, PKM2, has also been found to be expressed in embryonic, proliferating, and tumor cells, and it has been considered to be crucial for the metabolism and growth of tumor cells. Recent studies have shown that PKM2 promotes cell proliferation and suppresses cell apoptosis in various tumors. In addition, it has been reported that the PKM2 knockdown affects the Akt and ERK protein kinases.