CTLA4 and breast cancer: Therefore, patients need to face a high recurrence rate and drug resistance.[10] With the development of medical technology, breast cancer treatment has gradually been systematized.[11] Recently, immunotherapy has provided new ideas for treating breast cancer, especially for breast cancer in an advanced stage.[12] For example, previous research suggested potential targets of immune checkpoint therapy, which included proteins such as cytotoxic T lymphocyte-associated antigen 4 and programmed cell death ligand 1 in breast cancer.[13]