Transient suppression of MLL-ENL in neonates prevents AML in most mice. (A) Overview of experimental design. (B) Kaplan-Meier survival curves for Tet-OFF-MLL-ENL mice after neonatal suppression of the transgene. The P value is indicated and reflects a comparison of mice that received a 4-week doxycycline (Dox) pulse, beginning at P0, to mice that did not receive doxycycline. Group sizes are indicated. Survival curves were compared by the log-rank test. (C-F) Spleen weights, white blood cell (WBC) counts, and hemoglobin (Hgb) and platelet counts for mice that survived for >1 year after transient MLL-ENL suppression. All mice were euthanized ∼12 months after birth. (G) Representative bone marrow cytospins for mice that developed AML, in the absence of doxycycline, and mice that survived for >1 year after transient MLL-ENL suppression. Scale bars indicate 100 μM. For panels C-F, CTL indicates control and ME indicates Tet-OFF-MLL-ENL genotypes.