CD274 and metastatic neoplasm: By targeting the T-cell cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) or the programmed cell death-ligand 1 (PD-1/PD-L1) coinhibitory receptors, ICIs, either as single agents or in combination, enhance antitumor T-cell activity, leading to unprecedented long-lasting tumor responses in patients with unresectable or advanced metastatic disease (2–6).