The mean genomic CNA were 29.7% in the HR+/HER2+ group, 19.5% in the HR+/HER2- group, 19% in the HR-/HER2- group, and 16.4% in the HR-/HER2+ group and did not significantly differ among the four subtypes of breast cancer (p = 0.15). Here, ERBB2 is linked to breast cancer.