ERBB2 and breast cancer: Notably, among the list of identified candidates exclusively found in the HER2+ BC cell line (Table 1) the most abundant was the driver proto-oncogene and key biomarker that characterizes this type of cancer, the human epidermal growth factor receptor 2 (ERBB2, also known as HER2) (31), verifying the reliability and validity of the described proteomic methodology.