Thalidomide-NH-PEG2-COOH is primarily utilized in the development of PROTACs (Proteolysis Targeting Chimeras), a cutting-edge approach in targeted protein degradation. This compound serves as a crucial linker component, connecting the thalidomide moiety, which binds to the E3 ubiquitin ligase cereblon, to a target protein ligand. The PEG2 spacer enhances solubility and flexibility, optimizing the molecule's ability to facilitate the ubiquitination and subsequent degradation of disease-causing proteins. Its application is particularly significant in cancer research, where it aids in the selective elimination of oncogenic proteins, offering a promising therapeutic strategy. Additionally, it is explored in the treatment of neurodegenerative diseases and other conditions driven by pathogenic protein accumulation.