HER2

Human epidermal growth factor receptor 2 encoded by the erb-B2 gene is a member of the EGF/ErbB growth factor receptor family. HER2 is a tyrosine kinase type 1 receptor involved in signal transduction pathways leading to cell growth and differentiation. Amplification of the HER2 gene and overexpression of its product were first discovered in breast cancer and are significantly associated with disease aggressiveness and poor prognosis. Since then, many studies have demonstrated that HER2 is also present in several other malignancies, including colorectal, ovarian, prostate, lung, and gastric cancer.