Cell cycle profile of cells treated with CEP-701. MV4-11 cells (upper panels) and HL60 cells (lower panels) were cultured in the absence (left panels) or presence (right panels) of 20 nM CEP-701 for 48 hours, then costained with annexin V and propidium iodide and analyzed by FACS. The graphs display propidium iodide (x-axis) staining of non-annexin V staining (ie, still viable) cells. The cells in G₂/S phase are designated in each graph with an arrow.