Experimental design and establishment of a murine leukemia model by Notch1 overexpression. Lin⁻Sca-1⁺ cells (CD45.2⁺) were isolated from BM of C57BL/6J mice. A total of 10⁷ BMNCs (CD45.1⁺) from B6.SJL mice were transplanted into lethally irradiated recipients (10 Gy, C57BL/6J) either with (leukemia group) or without (the control group) 10⁶ cells that were transduced with the MSCV-ICN1-IRES-GFP vector. The transplanted normal hematopoietic cells (CD45.1⁺GFP⁻) from the recipients were analyzed and sorted by flow cytometry at different time points (A). Resultant data are shown in all the figures except Figure 5. An additional control with a higher dose of normal congenic BMNCs was included in some experiments (supplemental Figure 2). A T-ALL feature of the affected mice is shown by an immature T-cell phenotype (supplemental Figure 1). The hosts receiving Notch1-transduced cells displayed leukemia symptoms, including increases of total leukemic cells (CD45.2⁺GFP⁺) in PB (B), WBCs in PB (C), and BM cellularity (D). Values are mean ± SD. *P < .05 (t test). The 100% penetrance of the leukemic development is shown in the survival curve (E). P < .01 (n = 15 each, Kaplan-Meier analysis).