Moreover, nanoscale immunoconjugates (NICs) on a natural biopolymer scaffold, poly(β-L-malic acid), were produced with covalently attached anti-CTLA-4 or anti-PD-1 for systemic delivery across the BBB and activation of local brain anti-tumor immune responses (Galstyan et al., 2019). Here, CTLA4 is linked to neoplasm.