According to recent studies, PD-L1 plays a specific tumor-intrinsic role in promoting cancer metastasis, development, and treatment resistance56.Our study demonstrated that downregulated PD-L1 expression, through overexpression of candidate miRs, in BC cell lines significantly inhibited cell proliferation along with induction of G0/G1 phase arrest and apoptosis induction. This evidence concerns the gene CD274 and cancer.