Receptor tyrosine-protein kinase erbB-2 is a protein that normally resides in the membranes of cells and is encoded by the ERBB2 gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently referred to as HER2 or CD340.
HER2 is a member of the human epidermal growth factor receptor family. But contrary to other members of the ERBB family, HER2 does not directly bind ligand.
