MCL1 and acute myeloid leukemia: Taken together, our research results show that ABT-199 combined with HHT exerts antileukemic activity in vitro and in vivo, likely through inhibiting the expression of BCL-2 and MCL-1, as well as the FLT3-STAT5 signaling pathway, and provide potential benefits and a clinical application approach for ABT-199 and HHT in AML patients.