Most recently, based on the results of TROPICS-02 clinical study (NCT03901339), FDA approved SG for unresectable locally advanced or metastatic hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative breast cancer (mHR+/HER2- BC) in patients that have progressed after endocrine-based therapy and at least two additional systemic therapies. This evidence concerns the gene ERBB2 and breast cancer.