Selective estrogen receptor degrader
A selective estrogen receptor degrader or downregulator (SERD) is a type of drug that selectively binds to the estrogen receptor (ER) and induces its degradation, and thus causes its downregulation. SERDs are used in the treatment of estrogen receptor-positive breast cancer, particularly in cases where tumors have developed resistance to other forms of endocrine therapy, such as selective estrogen receptor modulators (SERMs) or aromatase inhibitors.
Source: Wikipedia — Selective estrogen receptor degrader (CC BY-SA 4.0)