ERBB2 and breast cancer: Potential working targets of this molecular pathway are changes in the HER2 gene itself (known as ERBB2) [51], amplification, and overexpression of HER2. Anti-HER2 therapy with targeted agents, pertuzumab and trastuzumab, showed significant improvement in outcomes in patients with other types of cancer, such as breast cancer and gastrointestinal tumors (gastric cancer and gastroesophageal cancer [51].