PDK1 and neoplasm: Moreover, since the tumor environment promotes glycolysis resulting in energy production in tumor cells, [22] we analyzed the expression of key enzymes involved in glycolysis including hexokinase-2 (HK2), pyruvate dehydrogenase kinase-1 (PDK1), and lactate dehydrogenase A (LDHA) in the presence or absence of co-culture with CAF, using western blotting.