PDCD1 and neoplasm: To determine how the neuro-immune landscape changes in response to combi-ICI therapy, we used flow cytometry to comphrehensively characterize differences in immune cell subpopulations, including both lymphoid and myeloid cell populations, in brains of control and tumor-bearing mice, receiving CTLA-4 and PD-1 blockade 72 hours after the last dose of combi-ICI treatment (Fig. 5A, Fig. S1).