OPA1 and acute myeloid leukemia: We further used carboxyfluorescein succinimidyl ester (CFSE) labeling [30, 31] to investigate AML cell proliferation in leukemic cells grown in methylcellulose, and we observed that MFN2 or OPA1 depletion significantly enhanced CFSE retention compared to the control, showing that mitochondrial fusion inhibition decreased AML cell proliferation ex vivo (Fig. 3D).