As the binding of PD-L1 to PD-1 results in dysfunction of cytotoxic T lymphocytes (CTL) and loss of antitumor immunity, reactivation of dormant TILs by PD-1/PD-L1 inhibitors could represent a promising strategy in PD-L1 up-regulated breast cancer. This evidence concerns the gene PDCD1 and breast carcinoma.