Recent large phase III clinical studies, KEYNOTE-756 (NCT03725059, n = 1,278) and CheckMate-7FL (NCT04109066, n = 510), showed that the pCR rate in the ICI treatment group was significantly improved compared with the pCR rate in the control group, which confirmed the prospect of immunotherapy in treating HR+/HER2– breast cancer. This evidence concerns the gene ERBB2 and breast cancer.