Overview:

The widely expressed EGFR receptor tyrosine kinase family consists of 4 members: EGFR, HER2, HER3 and HER4. These kinases share up to 70% sequence homology in their extracellular domains. Signaling involves the combinatorial dimerization of the four known family members and is mediated by at least 8 different hormones, including EGF and the heregulins. Heterodimerization of HER2 with HER3 or HER4 enhances the HER2’s ability to bind Heregulin, leading to enhanced downstream tyrosine phosphorylation. These RTKs are implicated in many human cancers and strong concurrent expression of HER3 and HER2 leads to poor outcomes.

References:

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