A critical mediator of the Warburg effect is pyruvate kinase M2 isoform (PKM2), a tumour-specific isoform of the glycolytic enzyme pyruvate kinase (PK), which catalyses the synthesis of pyruvate and ATP, using phosphoenolpyruvate (PEP) and ADP as substrates21, 22, 23, 24. This evidence concerns the gene HK1 and neoplasm.