ERbeta: a novel estrogen receptor offers the potential for new drug development.

There is increasing interest in developing better drugs for improving the health of women. Because of the multiple target organs for estrogens and the occurrence of both beneficial and unwanted effects during treatment, the key to improvement in drug therapy is the development of estrogen receptor modulators with better tissue selectivity. The recent discovery that there are not one but two estrogen receptors, ERalpha and ERbeta, each with its unique tissue distribution and with differing and sometimes opposing actions on certain genes, promises new hope for the development of novel, tissue-selective estrogens. Our present knowledge of the tissue distribution of ERalpha and ERbeta suggests that development of selective therapies for treatment and/or prevention of menopausal symptoms, osteoporosis, cardiovascular disease, type II diabetes, Alzheimer's disease and urinary incontinence is an achievable goal in the foreseeable future. Furthermore, it is possible that future estrogen therapy might be beneficial for men.