Alongside with TNBC (corresponding to the term “basal-like” in genomic analyses), the other three BC subtypes consist of luminal-A tumors that account for over 40% of the patients, express ERs/PRs only and have a relatively good prognosis; luminal-B tumors that express ERs/PRs but can also carry HER2 amplification or relatively high ki67 levels; and HER2+ tumors that lack ERs and PRs [18,19,20]. This evidence concerns the gene ERBB2 and breast cancer.