In the carriers of germline pathogenic variants in BRCA1 or BRCA2, olaparib treatment has been shown to lead to superior progression-free survival when compared to standard therapy in individuals with HER2-negative metastatic breast cancer [87], and to longer disease-free survival in individuals with high-risk HER2-negative early breast cancer when compared to placebo [88]. This evidence concerns the gene ERBB2 and breast cancer.