ERBB2 and breast cancer: ERBB2, a member of the ERBB family of receptor tyrosine kinases (RTKs) (EGFR/ERBB1, ERBB2, ERBB3, and ERBB4), is overexpressed in approximately 15–20% of human breast cancers and its expression is highly associated with poorer overall survival (Nahta and Esteva, 2006; Murthy et al., 2016; Ethier et al., 2021).