1.   A synthetic hormone which targets estrogen receptors in the bone and heart but not in the reproductive system, the drug targets heart disease as well as osteoporosis.

2.   According to scientific presumption, a person without estrogen receptors should have died in the womb, or perhaps ended up with a grossly distorted central nervous system.

3.   But certain breast cancers whose cells have estrogen receptors can be fed by estrogen.

4.   Cancers that have the estrogen receptor, for example, generally have a better prognosis and respond better to the drug tamoxifen.

5.   Dr. Katzenellenbogen, a professor of physiology and cell biology, has been studying estrogens and the estrogen receptor for a quarter-century.

6.   Estrogen fuels the growth of tumor cells in those cancers that have the estrogen receptors.

7.   He proposed that, even without working estrogen receptors, the man may still be responding to his inherent estrogen signals in subtle ways.

8.   Instead, estrogen works directly on blood vessels, through at least two estrogen receptors, and possibly through another mechanism too.

9.   Like estrogen itself, the drug locks onto estrogen receptors, blocking or displacing the hormone, but without stimulating malignant cells.

10.   Tamoxifen acts by blocking estrogen receptors on tumor surfaces, thus preventing hormones from latching on and signaling the tumor to grow.