CD4⁺ T_EMs mediate GVL against mCP-CML without causing GVHD. B6 mice were irradiated and reconstituted with T cell–depleted B6^bm12 BM, with B6 mCP-CML with no T cells, or with 5 × 10⁵ T_N or 10⁶ T_EM B6^bm12 CD4 cells. (A) Shown is survival data combined from 2 independent experiments. P < .001 for recipients of T_EMs versus only T cell–depleted BM. (B) Representative serial flow cytometry of peripheral blood. Each row represents serial bleeds of individual mice. Data from 2 T_EM recipients are shown to illustrate the types of responses we observed. Numbers on plots are percentages of total cells within the rectangles. (C) Numbers of NGFR⁺ cells in the peripheral blood of mice that underwent transplantation taken at different time points. Each symbol represents an individual animal; solid lines are mean values. P < .002 comparing T_Ns versus T_EMs from day 15 onward.