Blockade of RAR signaling in donor T cells does not abort the GVL effect. Lethally irradiated BALB/c recipients were transplanted with 10⁷ T-cell–depleted BM cells with or without 3 × 10⁵ A20-lymphoma cells on day 0. Subgroups were transplanted with 5 × 10⁶ splenocytes from dnRARα (open circles) and dnRARα-CD4^Cre (filled triangles) mice also on day 0. (A-C) Survival, weight, and clinical GVHD scores of lethally irradiated BALB/c recipients transplanted with BM cells only (filled squares), BM cells + A20 (filled circles), or with A20 + 5 × 10⁶ splenocytes from dnRARα (open circles) or dnRARα-CD4^Cre (filled triangles) donor mice. (D) Tumor growth was monitored by luciferase imaging at 1, 2, 3, 4, 6, 8, and 15 weeks after BMT. (E) The frequency of CD8⁺ cells expressing granzyme B was analyzed in spleen on day 14. Data were obtained from 1 experiment each with 5 to 10 (A-D) or 7 to 8 (E) mice per group. (A) BM cells + A20 vs dnRARα-CD4^Cre + A20; P < .001. dnRARα+ A20 vs dnRARα-CD4^Cre + A20; P < .001. (B-C) dnRARα+ A20 vs dnRARα-CD4^Cre + A20 on day 6 to day 27; P < .001. (D) BM cells + A20 vs dnRARα-CD4^Cre + A20 at 1, 2, 3, and 4 weeks; P < .001. dnRARα+ A20 vs dnRARα-CD4^Cre + A20; P = not significant (ns).