CD8A and neoplasm: Using the four-tier scoring system [28,29], we found that the grade for tumor infiltrating CD8+ cells for B16-OVA tumor-bearing mice treated with CPI’s alone or in combination with SLA–OVA (adm) was 1 to 2 at the tumor margin and 0 to 1 in tumor nests; conversely, B16-OVA tumor-bearing mice injected with the vehicle alone had a grade of 0.