Accelerated LTI is ineffective in immunodeficient Rag2^−/−mice, mice depleted of CD8⁺T cells, and Batf3^−/−mice lacking antigen cross-presenting CD8⁺and CD103⁺DCs. Mice were injected with 2 × 10⁵ lymphoma cells to induce subcutaneous tumors in the flank. Changes in tumor volume after accelerated LTI in wild-type mice (A), Rag2^−/− mice (B), anti-CD8 T-cell mAb–treated mice (C), anti-CD4 T-cell mAb–treated mice (D), and Batf3^−/− BALB/c mice (E). Fractions of mice alive and in complete remission at day 60 are shown. (F) Survival of tumor-bearing mice from each group after irradiation or not treatment. There were significant differences in survival in the groups with untreated tumors vs tumors treated with accelerated LTI in wild-type (WT) mice (P < .0001), WT vs Rag2^−/− mice (P < .0001), WT vs CD8 TCD mice (P < .0001), and WT vs Baft3^−/− mice (P < .0001, Mantel-Cox test). (G) Fraction of mice in (A-E) that had different patterns of tumor spread on autopsy. LN, lymph nodes; mets, metastases.