PDCD1 and cancer: Such AVB could also act as a drug storage reservoir to sequentially release melphalan (Mel), a small-molecule drug used for arterial infusion chemotherapy against intraocular malignant tumors (32), and anti–programmed cell death ligand-1 (αPDL1), an immune checkpoint blockade antibody to restore T cell function by blocking the PD-1/PD-L1 pathway (33–35).