PDP1 and cancer: In several different cancer cell lines, PDK1 inhibitors can reduce glycolysis in the cytoplasm, downregulate PDH phosphorylation, upregulate the mitochondrial respiration, reverse mitochondrial hyperpolarization, activate several proteins in the apoptotic signaling pathway, and then induce cell apoptosis.49 A decrease in PDH expression is important for the aberrant preferential activation of glycolysis in cancer cells under normoxic conditions.