(A) Experimental design to compare tumor growth and immunological changes in WT and IRAK3-KO mice. (B) Syngeneic breast cancer cell line EO771 (400,000 cells per mouse, WT = 9, KO = 11, mean ± SEM) or lung cancer cell line LLC1 (200,000 cells per mouse, WT = 5, KO = 4) were injected subcutaneously in WT or IRAK3-KO mice. Tumor growth and survival of the animals were shown in a representative experiment of 2 repeats. (C) Oncogene-driven murine Ret melanoma cells (50,000 cells per mouse, WT = 7, KO = 10, mean ± SEM) or MYCN-amplified 9464D neuroblastoma cells (600,000 cells per mouse, WT = 7, KO = 6, mean ± SEM) were injected s.c. in WT or IRAK3-KO mice. Tumor growth of individual mouse and tumor size distribution at the study endpoints were shown. Representative experiment of 3 repeats. (D) Rat IgG2a isotype or a CSF-1R depleting antibody was i.p. injected into WT or IRAK3-KO mice in 100 μL PBS 3 days prior to implantation of Ret melanoma cancer cells (50,000 cells per mouse s.c.). Tumor volumes of individual mice were shown as mean ± SEM. The effect of CSF-1R antibody (clone AFS98) on tumor-bearing IRAK3-KO mice was observed in 3 individual experiments. (E) To study the immunological changes in size-matched tumors, EO771 cells (200,000 per mouse) were injected s.c. in WT or IRAK3-KO mice. Mice bearing comparable sizes of tumors (WT = 3 and KO = 4) on day 39 after injection were selected for FACS analysis. (F and G) Immunological changes and (H) correlation between PD-1⁺CD38⁺ cytotoxic T cells and MHCII on dendritic cells in tumor tissues were shown in tumor-bearing KO mice (n = 4). (I) Changes of CD4⁺ T cell subsets in spleens of the tumor-bearing mice were shown. All studies used age-matched female WT or IRAK3-KO mice. Statistical tests were performed using unpaired t tests. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.