Cell cycle analysis of freshly isolated AML cells. Peripheral blood mononuclear cells from the indicated patients were cultured for 48 hours in the presence of IL-3 and GM-CSF and in the presence or absence of 1000 ng/mL GO. Cell cycle analysis was then performed. The percentages of cells in the sub-G₁, G₀ /G₁, S, and G₂/M phases of the cell cycle are indicated in each panel.