We analyzed the frequency of SIINFEKLMHC‐I tetramer expressing CD8+ T cells in total naïve CD8+ OT1 T cells and found that the frequency of SIINFEKLMHC‐I tetramer expressing CD8+T cells was significantly increased in the naïve CD8+ OT1 T cells that were cocultured with the Arf1‐ablation‐stimulated‐DCs (Figure 5b,c), indicating increased tumor antigen‐specific CD8+ T cells. Here, ARF1 is linked to neoplasm.