PFKM and idiopathic pulmonary fibrosis: TGF-β-stimulated IPF fibroblasts have been shown to exhibit higher transcript abundances of important rate-limiting enzymes encoding glycolytic enzymes, such as pyruvate kinase muscle isozyme M2 (PKM2), phosphofructokinase 1 (PFK1), and hexokinase 2 (HK2) (26, 27).