Among these cases, the hormone receptor(HR) -positive and human epidermal growth factor receptor-2 negative (HER2-) breast cancer subtypes were the most prevalent, accounting for approximately 65%∼70% of all metastatic breast cancers (Giuliano et al., 2019; Babcock et al., 2020; Howlader et al., 2014). This evidence concerns the gene ERBB2 and breast cancer.