Epidermal growth factor receptor (EGFR), Erb-B2 receptor tyrosine kinase (ErbB2), and Erb-B4 receptor tyrosine kinase (ErbB4) (EGFR (for Epidermal growth factor receptor), ErbB2 (for Erb-B2 receptor tyrosine kinase), ErbB4 (for Erb-B4 receptor tyrosine kinase))

The ErbB receptor family consists of four structurally related receptor tyrosine kinases: Epidermal growth factor receptor (EGFR, also known as ErbB1/HER1), Erb-B2 receptor tyrosine kinase (ErbB2/HER2/Neu), Erb-B3 receptor tyrosine kinase (ErbB3/HER3), and Erb-B4 receptor tyrosine kinase (ErbB4/HER4). These receptors possess an extracellular ligand-binding domain, a transmembrane domain, and an intracellular tyrosine kinase domain. They mediate cellular responses after ligand binding and dimerization, resulting in autophosphorylation and recruitment of intracellular signaling proteins. EGFR and ErbB2 are critical drivers in several cancers; targeted therapies against them are among the most successful examples of precision oncology. ErbB4 is less studied but plays important roles in neural development and is also implicated in some cancers. When activated abnormally, these receptors contribute to oncogenesis, tumor progression, and therapy resistance[1][2][3][5][7][9]. EGFR/ErbB2/ErbB4 are collectively key drug targets—yet each functions distinctly; in clinical and research contexts, they are usually considered separately for therapeutic decision-making. The use of the combined "EGFR/ErbB2/ErbB4" nomenclature is inaccurate for structured data or mechanistic studies, so the grouping is best split into its respective members for detailed annotation[1][5][9].

Other names

ErbB1HER1HER2NeuHER4ErbB receptor familyEGFR familysubclass I RTK superfamily

Small molecule kinase inhibitors (inhibit ATP binding in tyrosine kinase domain) Monoclonal antibodies (block ligand binding or receptor dimerization) Antibody-drug conjugates (targeted delivery of cytotoxic agents) Downregulation, degradation of receptor, blockade of downstream signaling