CD274 and breast cancer: Indeed, previous reports showed that EVs carrying PD-L1 have a correlation with immunosuppression and tumor progression in patients with glioblastoma, lung cancer, melanoma, and breast cancer.56–58 We further confirmed the induction of PD-L1 and IFN-γ expression and the higher levels of mtDNA contents in the plasma of patients with OSCC compared with the normal group.