"Antiestrogen"^^ . "CHEBI:50837"^^ . . . "Substances that inhibit or antagonize the biosynthesis or biologic effects of estrogens by either antagonizing the responsiveness of estrogen sensitive tissues or competing with their binding sites.NCI" . "A substance that keeps cells from making or using estrogen (a hormone that plays a role in female sex characteristics, the menstrual cycle, and pregnancy). Estrogen blockers may stop some cancer cells from growing and are used to prevent and treat breast cancer. They are also being studied in the treatment of other types of cancer. An estrogen blocker is a type of hormone antagonist.NCI-GLOSS" . "C481"^^ . . "AntiestrogenPTNCI" . "Chemical Viewed Functionally"^^ . "estrogen blockerPTNCI-GLOSSCDR0000648588" . "AntiestrogenicSYNCI" . "Estrogen AntagonistSYNCI" . "Anti-EstrogensSYNCI" . "Antiestrogen"^^ . "AntiestrogensSYNCI" . "C0014930"^^ . "Antiestrogen"^^ . "CHEBI:50751"^^ . "Estrogen InhibitorSYNCI" . "antiestrogenPTNCI-GLOSSCDR0000044813" .