HOXA9 and neoplasm: To establish the role played by phagocytes in AML, we used clodronate liposomes (CLs) to deplete phagocytic macrophages in a series of experiments using 2 AML in vivo models: myeloid ecotropic viral integration site 1/homeobox A9–driven (MEIS1/HOXA9-driven) AML (36), containing a GFP and a luciferase reporter, and meningioma 1–driven (MN1-driven) AML (37), containing a GFP reporter, both of which allowed for detection using in vivo imaging as well as measurement of tumor burden by the presence of GFP+ cells (Figure 1A).