Earlier onset of Aml1-excised MLL-ENL leukemia. (A) BM cells from Aml1^f/f and Aml1^Δ/Δ mice were transduced with MLL-ENL and transplanted into congenic mice. (B) Survival curves of the mice transplanted with Aml1^f/f and Aml1^Δ/Δ cells transduced with MLL-ENL. Data from 12 mice for each group are shown. Comparison of survival curve was performed using log-rank test. (C) Flow cytometric analyses of the leukemic cells from transplanted mice. (Top) Representative fluorescence-activated cell sorter plots. (Bottom) Percentages of cells expressing indicated surface markers in each group (mean ± SD).