WORLD OF REPRODUCTIVE BIOLOGY Endometriosis Takes a Hit

Compounds that target estrogen receptors (ERs) show promise as a potential treatment for endometriosis in a study of both a mouse model of the disease and in human cells. Women with endometriosis suffer from painful invasive lesions, resulting from attachment of endometrial tissue to sites outside of the uterus. The hormone estrogen drives the disease (the lesions have aberrant ER expression), but the condition is also thought to involve an inflammatory response associated with the lesions. Aromatase inhibitors or other drugs that choke off the supply of estrogen are currently the standard for care. But these drugs are imperfect—for instance, they can result in side effects such as reduced bone density and changes to fertility. Treatment is often a struggle for people with the condition, which is 10 to 14 percent of reproductive-age women. To attempt to circumvent such problems, Yuechao Zhao et al. tested two newly developed ER ligands [1]. These ligands block multiple activities of estrogen but have been optimized to be particularly effective at blocking the hormone's pro-inflammatory