CD28 and central nervous system cancer: Anti-PD-L1 is able to disrupt the cis interaction between PD-L1 and B7-1 (CD80) on DCs, allowing CD80 to activate T cells via CD28.40 Anti-PD-L1 is also able to act directly on tumor cells, driving cytokine production and in vivo phagocytic activity of glioma TAMs in some contexts.41 Finally, dual CTLA-4/PD-1 blockade can induce apoptosis of tumor-specific T cells in preclinical models with low tumor burden.42