Thalidomide-O-amido-PEG3-C2-NH2 (TFA) is primarily used in the field of targeted protein degradation, particularly in the development of PROTACs (Proteolysis Targeting Chimeras). Its structure allows it to act as a linker, connecting a target protein-binding ligand to an E3 ubiquitin ligase recruiter, facilitating the degradation of specific proteins. This application is crucial in drug discovery and research, especially for targeting disease-causing proteins that are traditionally difficult to inhibit. It is also utilized in chemical biology studies to explore protein function and interactions, aiding in the development of novel therapeutic strategies for conditions like cancer, neurodegenerative diseases, and autoimmune disorders.