KMT2A and leukemia: Moreover, in analogy to SM6p2 and SM6p3, the intrinsically unresponsive cells expressed significantly higher baseline levels of HIF1α compared to the sensitive MLL-r leukemia cells, confirming that intrinsically unresponsive MLL-r leukemia cells inherently present with a more glycolytic phenotype than the responsive cells (Fig. 4f).