KMT2A and acute myeloid leukemia: Basal OCR of MLL/AF9 blast cells in all AML mice was significantly higher than that of the control murine HPCs; however, no significant difference was found in terms of maximal OCR because of the metabolic heterogeneity between the mice (Figure 2E,F and Figure S4), suggesting that MLL/AF9 AML cells have significantly upregulated OXPHOS.