A recent meta-analysis, including 11 studies totaling 1697 BC patients, described that a high PD-L1 expression on tumor cells was associated with a high tumor stage (T2-4 vs. Ta-1; OR 3.9, p < 0.001) and the presence of distant metastasis (OR 2.5, p = 0.012). This evidence concerns the gene CD274 and neoplasm.