Description: CVRARTR is an antagonist of programmed cell death ligand 1 (PD-L1) with a KD of 281 nM. It induces internalization of PD-L1 and decreases its levels on the cell surface. CVRARTR restores cytokine secretion and T cell proliferation in CT26 cells and demonstrates antitumor efficacy in CT26 syngeneic mouse models.