E3 ligase ligand-linker conjugates 17 are primarily utilized in the field of targeted protein degradation, particularly in the development of PROTACs (Proteolysis Targeting Chimeras). These conjugates play a critical role in bridging the E3 ubiquitin ligase and the target protein of interest, facilitating the ubiquitination and subsequent degradation of the target protein by the proteasome. This approach is highly valuable in drug discovery and therapeutic research, especially for targeting undruggable proteins or those involved in disease pathways, such as cancer, neurodegenerative disorders, and inflammatory conditions. By enabling selective degradation, these conjugates offer a powerful tool for modulating protein levels and studying protein function in biological systems.