Thalidomide-NH-PEG3-propionic acid is primarily used in the development of PROTACs (Proteolysis Targeting Chimeras), a cutting-edge technology in drug discovery. It serves as a linker molecule, connecting a target protein-binding ligand to an E3 ubiquitin ligase recruiter. This facilitates the targeted degradation of specific proteins, offering a novel approach to treating diseases like cancer, neurodegenerative disorders, and autoimmune conditions. Its PEG3 spacer enhances solubility and flexibility, improving the efficiency of the PROTAC system. Additionally, it is utilized in research to study protein-protein interactions and cellular pathways, aiding in the understanding of disease mechanisms and the development of targeted therapies.