Rapamycin enhances apoptosis in primary AML cells. Primary patient samples were thawed and incubated as for Figure 3. Cells were harvested, pelleted, and incubated with anti-annexin V-FITC and PI. Single-cell suspensions were analyzed by FACScan (Becton Dickinson). Early apoptotic cells were scored as annexin V positive, PI negative to exclude necrotic cells. (A) FACS data from a representative sample. (B) Graph of percentage early apoptotic cells for 3 different patient samples indicated by white, hatched, or black bars.