has_role chemical entity drug role antiprogestin An antiprogestogen, also called an antiprogesterone or in the case of a synthetic agent, an antiprogestin, is a type of hormone antagonist in which that antagonizes or suppresses the actions of progesterone in the body, a sex hormone that plays a role in the menstrual cycle and pregnancy. Antiprogestogens may stop some cancer cells from growing and they are being studied in the treatment of breast cancer. An example of an antiprogestogen is mifepristone.[1][2 MESH:C076196 http://en.wikipedia.org/wiki/Antiprogestin Org 31710