Univariate regression analysis showed that PDL-1, CTLA-4, PD-1, FOXP3, MIC-B, miR-155, and miR-195expression were significantly associated with BC incidence (p < 0.001, 0.001, 0.001, 0.001, p < 0.001, 0.001, and 0.001; respectively). Here, PDCD1 is linked to breast cancer.