CTLA4 and breast cancer: The application of PD-1/PD-L1 and CTLA-4 have been shown good curative effect on improving patients’ prognosis in hepatocellular carcinoma, non-small cell lung carcinoma, breast cancer and so on (Chae et al., 2018; Vaddepally et al., 2020; Lee et al., 2021; Chen Y. et al., 2022; Zhao et al., 2022).