The Epidermal Growth Factor (EGF) system is expressed in healthy premenopausal endometrium. We describe the expression of the four receptors, HER1, HER2, HER3, HER4 and the six ligands amphiregulin, transforming growth factor alpha (TGF-alpha), heparin binding EGF like growth factor (HB-EGF), betacellulin, epiregulin and EGF in endometrioid endometrial cancer.