In addition, we confirmed superior antitumor effects of α4-1BB therapy in tumor-bearing A2BR–/– mice compared with WT mice without ACT (Supplemental Figure 8A), which correlated well with increased infiltration, proliferation, and IFN-γ production of endogenous tumor-infiltrating CD8+ T cells (Supplemental Figure 8, B–D). Here, CD8A is linked to neoplasm.