Since the SARE also contains a HIF-1-binding site (HBS), we used point-mutational analysis, electrophoretic mobility super-shift assays (EMSAs) and a HIF-1α deficient CHO cell line to investigate the importance of HIF-1, the HIF-1 binding site consensus (HBS), and the base immediately 5′ to this, in the anoxic and hypoxic inducibility of the SARE in human cancer cells. Here, HIF1A is linked to cancer.