PROTAC ER Degrader-4 is primarily used in research settings to study targeted protein degradation, specifically focusing on the estrogen receptor (ER). It is designed to induce the degradation of ER, which is particularly relevant in the context of hormone-dependent cancers, such as breast cancer. By leveraging the PROTAC (Proteolysis Targeting Chimera) technology, this compound facilitates the removal of ER proteins from cells, offering a potential therapeutic strategy to inhibit cancer cell growth and proliferation. Its application is significant in developing novel treatments for ER-positive cancers, as it provides a way to bypass resistance mechanisms often seen with traditional hormone therapies. Additionally, it serves as a valuable tool in understanding the molecular pathways involved in ER signaling and degradation.