Differential effects of KRN7000 and C20:2 on GVHD and GVL. (A) Irradiated B6D2F₁ mice received whole spleen from G-CSF–mobilized syngeneic donors, followed by control diluent, C20:2, or KRN7000 IP on days +1 and +4. Cohorts of mice received leukemic challenge with P815^Luc+ or no challenge (control + P815^Luc+, n = 8; C20:2 + P815^Luc+, n = 5; KRN7000 + P815^Luc+, n = 5; no leukemic challenge, n = 4-6). Overall survival by Kaplan-Meier analysis. Images are representative biphotonic bioluminescence images captured using the Xenogen system. Color scale represents signal intensity code (photons/s/cm²/sr). (B) Irradiated B6D2F₁ mice received whole spleen from G-CSF–mobilized B6 allogeneic donors plus P815^Luc+, followed by control diluent, C20:2, or KRN7000 on days +1 and +4 (control and C20:2, n = 24 per group; KRN7000, n = 16). Overall survival by Kaplan-Meier analysis; combined data from 3 identical experiments. *P < .001 KRN7000 vs control or C20:2. **P = .02 control vs C20:2. (C) GVHD mortality by Kaplan-Meier analysis for the experiments in panel B. (D) Leukemic mortality by Kaplan-Meier analysis for the experiments in panel B. ***P = .0379 (control vs C20:2).