BIM knockout and MCL-1 overexpression rescue cell death of MV4-11 cells treated with quizartinib alone or in combination with dexamethasone. (A) Immunoblot showing BIM-knockout (pooled single clones) in MV4-11 cells. (B) Quantification of Annexin-V positive dead cells in BIM-knockout (KO) or wild-type MV4-11 cells treated with the indicated drugs (100 nM quizartinib and 50 µM dexamethasone) for 48 hours and subjected to APC-Annexin-V and 7-AAD staining and FACS analysis. (C) A representative immunoblot (n = 2) showing MCL-1 degradation in cells expressing Flag-MCL-1^KR as well as wild-type cells following treatment with the indicated drugs (100 nM quizartinib and 50 µM dexamethasone) for 18 hours. (D) Quantification of Annexin-V positive dead cells in Flag-MCL-1^KR–expressing cells or WT cells treated with the indicated drugs (100 nM quizartinib and 50 µM dexamethasone) for 48 hours by APC-Annexin-V and 7-AAD staining and FACS analysis. (E) Representative images of FACS analysis of APC-Annexin-V and 7-AAD stained MV4-11 cells following treatment with quizartinib (100 nM) alone or in combination with MCL-1 inhibitor MIK-665 at the indicated concentrations for 48 hours. (F) Three-dimensional graph showing the synergy score of quizartinib and MIK-665 combination after 48 hours in MV4-11 cells.