Tumor cells upregulate PD-L1 which binds to PD-1 on T cells and reduces T cell effector function and contributes to T cell “exhaustion.” Monoclonal antibodies targeting the PD-1/PD-L1 axis have been explored, including 64Cu-labeled anti-PD-1 antibodies [35] and an 89Zr-labeled nivolumab in non-small-cell lung cancer patients [36]. This evidence concerns the gene CD274 and neoplasm.