HER2 is an extracellular receptor—a receptor tyrosine kinase - that when activated, sets off signal transduction through several pathways that stimulate cell proliferation and cell growth; if overexpressed it can cause uncontrollable growth. HER2 positive breast cancer is caused by ERBB2 gene amplification that results in overexpression of HER2 in approximately 15-30% of breast cancer tumors. Like many receptors HER2 normally combines another protein in order to function (a process called dimerization); it can bind with a second HER2 receptor (acting as a homodimer) and it can heterodimerize with a different receptor of the HER family. The most potent dimer for activating signalling pathways is HER2/HER3. The epitope for<unk>  is the domain of HER2 where it binds to HER3, and<unk>  prevents the HER2/HER3 dimer from forming, which blocks signalling by the dimer. Trastuzumab is another monoclonal antibody against HER2; its epitope is the domain where HER2 binds to another HER2 protein. The two mAbs together prevent HER2 from functioning.
Pertuzumab
Gatipotuzumab
Theralizumab
Caplacizumab
Elotuzumab
Idarucizumab
Risankizumab
Alemtuzumab