Aromatase inhibitors like AstraZeneca (nyse: AZN)'s tamoxifen were revolutionary in the treatment of breast cancer.

FORBES: Magazine Article

Aromatase inhibitors, like Arimidex, stop estrogen production completely by curtailing a hormone called aromatase.

FORBES: Searching For An Heir To Tamoxifen

Three aromatase inhibitors are set for tentative approval - anastrozole, exemestane and letrozole.

BBC: Earlier use of cancer drug backed

The participants were post-menopausal and had become resistant to certain hormone drugs called aromatase inhibitors that block production of estrogen.

WSJ: Breast-Cancer Drugs Raise Hopes

All aromatase inhibitors are not necessarily exactly the same.

FORBES: Magazine Article