Amphiregulin(AREG), also known as colorectum cell-derived growth factor, CRDGF, SDGF and AREG, is a member of the epidermal growth factor family and the amphiregulin family. Members of EGF family are cytokines that include 1 proteins such as EGF, TGFb, HBEGF, and the various heregulins. Amphiregulin is a single-pass membrane protein and contains one EGF-like domain. It plays a key role in epithelial development in various organs. Amphiregulin has a realationship with epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha). It is an autocrine growth factor as well as a mitogen for astrocytes, Schwann cells, and fibroblasts. As a bifunctional growth-modulating glycoprotein, amphiregulin inhibits growth of several human carcinoma cells in culture and stimulates proliferation of human fibroblasts and certain other tumor cells. Amphiregulin also may play a protective role in bleomycin-induced pneumopathy, probably through the activation of survival signals.