A DNA sequence encoding the human Amphiregulin protein sequence (containing the signal peptide sequence, N- and C-terminal propeptide sequences and the mature Amphiregulin sequence) was expressed in modified human 293 cells. Amphiregulin is an epidermal growth factor (EGF)-related glycoprotein that is expressed in a variety of tissues including ovary, placenta, lung, kidney, stomach, colon and breast. As an EGF-related growth factor, Amphiregulin is involved in the differentiation and proliferation of a wide range of cell types and these actions are mediated through binding to the EGF receptor. Amphiregulin plays an important role in neoplastic disease states. It has been demonstrated that Amphiregulin is over-expressed in a wide spectrum of cancers including prostate, colorectal, mammary, kidney, bladder, ovary, pancreas, lung, and gliomas. Amphiregulin levels also correlate with reduced survival in patients with non-small cell lung cancer and pancreatic cancer. Therefore, Amphiregulin may promote tumor progression in an autocrine fashion. Conversely, studies have also shown that Amphiregulin can inhibit proliferation of certain cancer cell lines such as A431 human epidermoid cancer cells. Recent studies indicate that Amphiregulin may also act as a protective factor in response to liver damage. Amphiregulin is synthesized as a 252 amino acid precursor glycoprotein with 3 potential N-glycosylation sites. It comprises a 19 amino acid signal peptide and 2 propeptide domains at the N-terminus and C-terminus. The C-terminus propeptide acts as a potential transmembrane domain. The mature form of Amphiregulin is predominantly 84 amino acids in length however a truncated 78 amino acid form has also been described. For a recent paper documenting a novel role for Amphiregulin please refer to Berasain C, et al. (2005) J Biol Chem. 280(19): 19012-20.