Epidermal growth factor receptor kinase domain and Human epidermal growth factor receptor 2 kinase domain (EGFR (also known as ERBB1) and HER2 (also known as ERBB2))

EGFR (epidermal growth factor receptor, also known as ERBB1) and HER2 (human epidermal growth factor receptor 2, also known as ERBB2) are closely related members of the ErbB family of receptor tyrosine kinases. Their kinase domains drive cellular signaling upon dimerization, which can occur as either homodimers or heterodimers. EGFR is activated by specific ligands (such as EGF and TGF-α), while HER2 does not have a known ligand but serves as the preferred dimerization partner for other ErbB receptors, greatly amplifying downstream signaling. Upon activation, these receptors autophosphorylate tyrosine residues in their intracellular domains, triggering pathways that control cell proliferation, differentiation, and survival. Both EGFR and HER2 kinase domains are established therapeutic targets in cancer, with numerous drugs directly targeting their kinase regions or dimerization interfaces. Aberrations such as overexpression, amplification, and activating mutations are common in various cancers, making them critical biomarkers and drivers of disease[1][2][3][4][5][6].

Other names

EGFR (epidermal growth factor receptor)ERBB1HER2 (human epidermal growth factor receptor 2)ERBB2ErbB kinase domainsHER family kinase domainsHER2/neu (for ERBB2)EGFR tyrosine kinase

Tyrosine kinase inhibition (blocks ATP binding to prevent phosphorylation), Receptor dimerization inhibition (prevents activation), Receptor downregulation or degradation, Monoclonal antibody-mediated blockade of ligand binding