CES1 and acute myeloid leukemia: To supplement western blot expression levels, intracellular flow analysis of hCE-1 in a smaller cohort of M2, M4 and M5 monocytoid AML samples was divided into tefinostat-sensitive primary AMLs (EC50 < 1 μM Ave) and tefinostat-resistant samples (EC50 > 2.5 μM).