M2-PK, also called pyruvate kinase M2, is the name of an isoenzyme of pyruvate kinase. Pyruvate kinase is a key enzyme in the cellular process of glucose metabolism (glycolysis), catalyzing the passage of phosphoenolpyruvate to pyruvate and generating energy in the form of adenosine triphosphate. This isoenzyme is expressed especially in cells in a state of rapid multiplication, as occurs in cancer cells, based on this circumstance and the property that has to pass unchanged through the intestine, forming part of the stool, can be used as a tumor marker and make its determination in feces with the purpose of detecting prematurely the existence of colon cancer.

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