Bardon, Ceder, and Kollberg were the first to demonstrate significantly increased activities of glycolytic enzymes such as hexokinase (HK), phosphofructokinase-1 (PFK1), pyruvate kinase (PKM) and lactate dehydrogenase (LDH) in activated fibroblasts from cystic fibrosis patients (204). Here, PFKM is linked to cystic fibrosis.