Estrogen receptors--known and unknown biological functions.

The present literature review includes the data available from 1995 to 2005 about the biological functions of estrogen receptors (ERs) and their role in tumorigenesis. The domain organisation,and cell and tissue localization of two estrogen receptors are described. The article reviews the well known function of these receptors as transcription factors and their less familiar extracellular "non-genome" effects.