KLF4 and breast cancer: In the current study we have comprehensively analyzed seven representative human breast cancer cell lines to determine the effect of hypoxia on the percentage of BCSCs and on the expression of pluripotency factors (NANOG, KLF4 and SOX2), m6A demethylases (ALKBH5 and FTO), and an m6A methyltransferase inhibitor (ZNF217).