Recent studies have confirmed that M2 macrophages, which exist in large numbers in the tumor microenvironment, can evade T-cell-mediated immune surveillance by inducing the upregulation of PD-L1 and promote the progression of breast cancer by promoting angiogenesis, immune escape, and immunosuppression37,38, while M0 macrophages are closely associated with distal metastasis of tumor cells and poor prognosis39. Here, CD274 is linked to breast cancer.