In addition, under hypoxic conditions in the cancer microenvironment, the transcription factor hypoxia inducible factor (HIF)-1 induces GLUT1, glycolytic enzymes, and pyruvate dehydrogenase kinase-1 (PDK-1) that limit pyruvate utilization for oxidative phosphorylation and enhance aerobic glycolysis [81,82]. Here, PDK1 is linked to cancer.