Receptor protein tyrosine kinase erbB‑2 (HER2)

Receptor protein tyrosine kinase erbB‑2 (HER2) is a transmembrane receptor tyrosine kinase belonging to the EGFR/HER/ErbB family. It does not bind a direct ligand but is activated through homo- or hetero-dimerization with other family members, leading to downstream signaling via MAPK, PI3K/Akt, and PKC pathways. HER2 plays a central role in cell proliferation and survival and is overexpressed in several cancers, making it an important therapeutic target.

Other names

ERBB2CD340Neu

Monoclonal antibodies bind to the extracellular domain, preventing dimerization and downstream signaling. Antibody-drug conjugates deliver cytotoxic payloads to HER2-expressing cells. Small molecule inhibitors block the intracellular kinase domain's activity, inhibiting phosphorylation and signaling.