Human Epidermal Growth Factor Receptor (HER)

The Human Epidermal Growth Factor Receptor (HER) family, also known as the ErbB family, comprises four closely related receptor tyrosine kinases: EGFR/ErbB1/HER1, HER2/ErbB2, HER3/ErbB3, and HER4/ErbB4. These receptors play critical roles in regulating cell growth, survival, differentiation, and migration. Activation occurs primarily through dimerization—either as homodimers or heterodimers—between two HER family members. This process is often triggered by extracellular ligands such as epidermal growth factor or neuregulins. Dimerization leads to transphosphorylation of intracellular domains on specific tyrosines, initiating multiple downstream signaling cascades that regulate cellular processes. Dysregulation—such as overexpression or mutation—is implicated in various cancers including breast cancer where amplification of the HER2 gene drives aggressive tumor behavior and serves as an important therapeutic target.

Other names

ErbB familyErbB1HER1EGFRErbB2HER2ErbB3HER3ErbB4HER4

Inhibition of HER receptor tyrosine kinase activity, blocking downstream signaling pathways such as MAPK and PI3K/AKT.