CD274 and neoplasm: Pembrolizumab, a selective, high-affinity human IgG1 monoclonal antibody (mAb) that blocks PD-L1 binding to PD-1 and CD80, is approved for the first-line monotherapy of patients with PD-L1-positive (tumor proportion score of 1% or more) tumors in the US (Azpicentral, 2022).