Establishment of xenograft model of ALL in NSG mice. (A) Lentiviral transduction efficiency of the pSLIEW vector into ALL#18, ALL#20, and REH cells was measured by flow cytometry analyses of EGFP fluorescence. (B-D) Four mice were IT injected with transduced ALL#18. (B) Progression of xenograft ALL#18 was followed by detection of luminescence intensity using noninvasive in vivo imaging, starting at 11 weeks after IT injection. (C) End point flow cytometry analysis of CD19⁺CD10⁺ leukemic cells in the bone marrow of xenograft ALL#18 mice. (Left) Dot plot presentation of CD19 vs CD10 expression of bone marrow cells from the mouse shown in panel B. (Right) The percentage of human CD19⁺CD10⁺ leukemic cells within the total bone marrow cell population of xenograft ALL#18 mice compared with noninjected (control) mice. Each circle represents the percentage of CD19⁺CD10⁺ cells in the bone marrow of 1 mouse. Horizontal lines represent the mean of each treatment group, *P < .01 (unpaired Student t test). (D, left) Spleens from 4 xenograft ALL#18 mice and from 1 noninjected (control) mouse. (Right) Weight of spleens from the 4 xenograft mice compared with spleens from 4 control mice. Each circle represents the spleen weight (g) of 1 mouse. Horizontal lines represent the mean of each treatment group, *P < .01 (unpaired Student t test).