By using OT-I mice, our study demonstrated that CD8+ T cells (99-100% OVA-specific CD8+ T cells) not only highly infiltrate KPC tumors but also preferentially localized in the tumor islet after IL-12+IL-18 expression, contrary to the control OT-I mice where most CD8+ cells are found in the stromal areas. Here, CD8A is linked to neoplasm.