Furthermore, it promoted CTL proliferation, as indicated by abundant Ki67+CD8+ T cells (Figure 2G), as well as the expression of tumor necrosis factor (TNF) receptor superfamily 18 (Tnfrsf18) and Tnfrsf9 (Figure S3D,E, Supporting Information), which are often upregulated when T cells are stimulated.[30] Furthermore, we observed an increase in TNFα+CD8+ and interferon‐gamma (IFNγ)+CD8+ T cells (Figure 2H,I), suggesting enhanced anti‐tumor CTL activity, and a decrease in cells positive for T cell exhaustion markers PD‐1 and TIM‐3 (Figure 2J,K). Here, TNFRSF9 is linked to neoplasm.