Amphiregulin （AREG） is a member of the epidermal growth factor family. It is an autocrine growth factor as well as a mitogen for astrocytes, Schwann cells and fibroblasts. It is related to epidermal growth factor （EGF） and transforming growth factor alpha （TGF-alpha）. AREG is considered a predominant propagator that mediates LH surge-regulated ovarian functions in an autocrine and/or paracrine manner. The protein interacts with the EGF/TGF-alpha receptor to promote the growth of normal epithelial cells, and it inhibits the growth of certain aggressive carcinoma cell lines. AREG is associated with normal tissue development and proliferation and with a wide variety of human cancers including colorectal cancer.