CD274 and breast cancer: The immune-checkpoint inhibitors (ICIs) targeting programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway have been used to treat selected cases of breast cancers according to the benefits found in clinical trials3,4 Agents which are used in this setting include pembrolizumab for metastatic and early-stage, high-risk TNBC5,6, and dostarlimab for advanced tumors of any type, including breast cancers, with DNA mismatch repair deficiency (dMMR)7.