Scheme 1. Schematic illustration of anti-PD-1 nanoMIP as a PD-1/PD-L1 antagonist. Anti-PD-1 nanoMIP blocks the interaction of PD-1 and PD-L1 by binding the PD-1 N-terminal epitope and steric hindrance, and the blockade actives the function of T cell and reverses the chemoresistance of tumor cells.