Treatment of Molm14 cells with FLT3 inhibitors. (A-B) Molm14 cells were exposed to quizartinib (10nM) or sorafenib (100nM) in suspension culture or coculture with BM stroma and analyzed for annexin V binding (A) and propidium iodide staining (B) by flow cytometry. (C-D) Molm14 cells were cocultured with stroma in the presence and absence of 10nM quizartinib for 24 hours, and then cells were collected and analyzed for morphology (C) and NBT reduction activity (D). (E) Molm14 cells were cocultured on stroma in the presence and absence of 10nM quizartinib. After 1 hour, cells were collected and lysates were analyzed by immunoblotting as described in “Immunoblotting.” (F) Molm14 cells were cocultured with stroma and quizartinib at the indicated concentrations. Cells were collected after 0, 4, 8, 12, and 24 hours of drug exposure and analyzed by immunoblotting for phosphorylated and total C/EBPα.