Amphiregulin expression is induced by phorbol ester, estrogen, androgen, and other EGFR ligands. In vitro, amphiregulin functions as an autocrine growth stimulator to drive proliferation of colon carcinoma cells, normal and oncogene-transformed mammary epithelial cells, cervical carcinoma cells, prostate cancer cells, and keratinocytes. Amphiregulin is important in the development of human placenta and murine mammary gland. It is reportedly overexpressed in human cancers of breast, colon, stomach and pancreas.