CTLA4 and breast cancer: In the study, the BC patients in the low-risk group were more sensitive to anti-PD-1 (P  < 2.22e−16) and anti-CTLA-4 therapy (P  < 2.22e−16), and the same conclusion was reached with combination treatment of anti-PD-1 and anti-CTLA-4 (Fig. 10E).