CD274 and neoplasm: Notably, TNBC exhibits a higher level of PD-L1 expression associated with the presence of tumor-infiltrating lymphocytes (TILs), and a higher degree of mutational burden compared with other subtypes of breast cancer4–8, suggesting that TNBC might be more immunogenic, and thus can be an attractive target of immunotherapy such as PD-1/PD-L1 blockade therapy.