Comparison of immunophenotypes at death in mice transplanted with p210 BCR/ABL or p210 BCR/ABL(ΔUBD). (A) WBCs were collected from p210 BCR/ABL–, p210 BCR/ABL(ΔUBD)–, and vector-transplanted mice when they became moribund. Cells were examined by flow cytometry for GFP expression and then stained for CD11b, Gr1, B220, and CD3 as indicated. Data shown are for peripheral blood. (B) Survival curves for secondary transplantations. A Mantel-Cox test yielded a value of P = .0007 (χ² = 11.5). The black circle indicates a mouse that died with splenomegaly and hepatomegaly. However, GFP⁺ cells were negative for major lineage markers, including CD11b, Gr1, B220, CD3, and Ter119. B-ALL, B-cell acute lymphoblastic leukemia.