PDK1 and breast cancer: In breast cancer, Lin28A and Lin28B enhance, whereas let-7 suppresses, aerobic glycolysis through regulation of pyruvate dehydrogenase kinase 1, or PDK1, in a hypoxia- or hypoxia-inducible factor-1 (HIF-1)-independent manner, suggesting direct regulation of the Lin28/let-7 axis in the modulation of glycolytic metabolism even at ambient oxygen levels [106].