CD274 and breast carcinoma: The programmed death 1 (PD-1) receptor and its ligand PD-L1 have become an important target in cancer immunotherapy.1 Therapies based on the immune checkpoint PD-1/PDL-1 complex have significantly improved the clinical outcome of lethal cancers such as lymphoma, melanoma, and lung and breast cancers.2 Overexpression of membrane bound PD-L1 by tumor cells attenuates T-cell signaling3 to evade immune surveillance due to its binding with T-cell membrane bound PD-1.