Triple‐negative breast cancer (TNBC) is a type of breast cancer (BC) that lacks the expression of oestrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 (HER2), which makes it unresponsive to targeted therapies commonly used in BC, such as hormonal therapy or the monoclonal antibody trastuzumab [1]. This evidence concerns the gene ERBB2 and breast cancer.