Background
ERBB3 is a member of the epidermal growth factor receptor family (EGFR). Because ERBB3 lacks its own intrinsic kinase activity, it cannot transmit signals to the cell through protein phosphorylation. ERBB3 binds to the ligand Neuregulin (NRG-1/-2), also known as heregulin (HRG-1/-2). Ligand binding induces a conformational change in ERBB3, thereby achieving dimerization, phosphorylation, and activation of signaling pathways. ERBB3 is expressed in the gastrointestinal tract, reproductive system, skin, nervous system, urinary tract, and endocrine system in normal adults. ERBB3 overexpression was observed in breast cancer, lung cancer, colorectal cancer, gastric cancer, head and neck squamous cell carcinoma, ovarian cancer, melanoma, prostate cancer, and bladder cancer.
