ErbB2 Protein

Background

ERBB2, also known as HER2 (human epidermal growth factor receptor 2), is a receptor tyrosine kinase that is part of the ERBB receptor family. This family consists of four closely related receptors: EGFR (ERBB1), HER2 (ERBB2), HER3 (ERBB3), and HER4 (ERBB4). These receptors play crucial roles in cellular signaling pathways regulating cell growth, differentiation, survival, and apoptosis. ERBB2 is particularly significant due to its role in breast cancer and other cancers, where its overexpression or gene amplification is associated with aggressive tumor behavior and poor prognosis. ERBB2 lacks a direct ligand-binding domain but acts as a co-receptor to enhance signaling when paired with other ERBB family members. Its importance in oncology has led to the development of therapies targeting HER2, such as monoclonal antibodies and tyrosine kinase inhibitors.