PKM2 is an isoenzyme of the glycolytic enzyme pyruvate kinase. This protein catalyzes the production of pyruvate and ATP from phosphoenolpyruvate. PKM2 interacting with Opa proteins, a bacterial outer membrane protein involved in gonococcal adherence to and invasion of human cells, is required for bacterial pathogenesis. It is specifically expressed at high levels in tumor cells, and can be measured in plasma of patients with advanced breast cancer.