HIF1A and cancer: Contrary to the expectation that HIF-1α would be activated by glycolytic metabolites in cancer cells [34], we observed that CD49fhi BCSCs (CD49fhiCD24hi, CD49fhiCD24low) demonstrated reduced expression of HIF-1α gene targets as well as of HIF-1α-inducible glycolytic genes compared with CD49fhi SCs (Fig. 3d, e).