PGK1 and cancer: In general, HIF-1α may specifically induce the enhanced expression of CAIX, lysyl oxidase (LOX) and glycolytic enzymes such as hexokinase-2, aldolase A, phosphoglycerate kinase 1 (PGK1) and pyruvate kinase M (PKM), whereas HIF-2α appears to preferentially up-regulate the gene products including TGF-α, Myc, cyclin D1 and embryonic stem cell-like markers such as Oct-3/4, Sox-2 and/or Nanog in cancer cells under normoxic and hypoxic conditions (Figs 1 and 3) [16, 106, 107, 117, 120, 121, 124–127].