Elevated levels of PD-L1 enhance the response to treatment with PD-L1 inhibitors.47 Breast cancer patients with increased lymphocytic infiltrates and elevated levels of PD-L1 have increased survival expectancy.48 A meta-analysis41 of all breast cancer patients without stratification strategies reveled increased probability of relapse-free survival for patients with higher expression of PD-L1 (Fig. 3b). This evidence concerns the gene CD274 and breast cancer.