PDCD1 and brain neoplasm: Galstyan et al. found that cytotoxic T-lymphocyteassociated antigen 4 (a-CTLA-4) and programmed cell death-1 (a-PD-1) loaded nano-biopolymer scaffold functionalized with AP-2 exhibited trans-BBB delivery and increased CD8+ T cells, NK cells and macrophages with a decrease of regulatory T cells in the brain tumor area [101].