CTLA4 and breast cancer: The new treatments for breast cancer are also discussed in this article, including the use of PARP, MAPK, CHK1, CDK 4/6 inhibitor, anticytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4) antibodies, and anti-programmed cell death protein 1 (anti-PD1)/ligand 1 (anti-PD-L1) antibodies.