CTLA4 and neoplasm: In this case, decorating therapeutic EVs with antibodies specific for programmed death receptor-1 ligand (PD-L1) would direct them towards PD-L1-expressing tumor cells, while anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibodies would support regulatory T cell targeting (Nazimek and Bryniarski, 2020b).