MCL1 and acute myeloid leukemia: In our research, we found that Bax expression was dramatically upregulated, whereas BCL-2 and MCL-1 levels were downregulated in ABT-199 plus HHT combination-treated cells, leading to a dramatic increase in the cleavage of caspase-3, which may be one of the ways that HHT enhances the promotive effect of ABT-199 on apoptosis in AML cell lines.