The BRD4 ligand-linker conjugate 1 is primarily utilized in the field of targeted cancer therapy. Its application revolves around the development of Proteolysis Targeting Chimeras (PROTACs), which are bifunctional molecules designed to degrade specific proteins within cells. This compound binds to BRD4, a protein often implicated in cancer progression, and recruits an E3 ubiquitin ligase to tag BRD4 for degradation by the proteasome. This targeted protein degradation approach offers a promising strategy for treating cancers that are dependent on BRD4 activity, such as certain types of leukemia and solid tumors. Additionally, it is used in research to study BRD4's role in gene regulation and epigenetic mechanisms, providing insights into novel therapeutic pathways.