AML stem cells require mTOR for survival of genotoxic stress. Cells were thawed, and 5 × 10⁶ cells per animal were injected immediately or incubated overnight in the presence of indicated compound. Etoposide was used at 5 μM and rapamycin at 10 μM. Cells were injected into sublethally irradiated mice and monitored for 7 weeks. Animals were humanely killed, bilateral femurs were harvested and analyzed for the presence of human cells. Percentage engraftment is indicated as percentage of human CD45⁺/CD33⁺ cells present. (C) Purified CD34 cells (1 × 10⁶) per animal were incubated overnight in the indicated conditions. Cells were injected in NOD/SCID mice as above and analyzed as above. In this case, analysis confirmed expression of CD45⁺CD33⁺ cells and CD45⁺CD19^- cells, indicating myeloid and lymphoid engraftment. For comparison, values shown are the percentage of CD45⁺CD33⁺ cells, but similar effects were seen comparing CD19⁺ cells or total CD45⁺ populations. Note that because of morbidity, some conditions show results of only 2 animals, and standard deviations in this experiment could not be calculated.