CD8A and breast cancer: To rule out the influence of cell mixture distribution in PBMCs on DNA methylation, we calculated the cell proportion according to EpiDISH method38, and found significantly higher monocytes proportion in BC patients than in controls, and NK cells proportion in BC were significantly lower than those in normal controls, but not in CD8+ T cells, CD4+ T cells, B cells and granulocytes (Supplementary Table 3).