Thalidomide-NH-PEG4-Ms is primarily utilized in the field of targeted protein degradation and PROTAC (Proteolysis Targeting Chimeras) development. Its structure combines a thalidomide moiety, which binds to E3 ubiquitin ligase, with a PEG4 linker and a mesylate group, enabling precise conjugation to target molecules. This compound is particularly valuable in designing bifunctional molecules that selectively degrade disease-causing proteins, such as those involved in cancer, neurodegenerative disorders, and inflammatory conditions. The PEG4 linker enhances solubility and flexibility, improving the pharmacokinetic properties of the resulting PROTACs. Additionally, the mesylate group allows for efficient attachment to nucleophilic groups on target proteins or small molecules, facilitating the creation of highly specific degraders. This chemical is instrumental in advancing research and therapeutic strategies focused on modulating protein levels in cells.