Thalidomide-PEG2-NH2 hydrochloride is a synthesized E3 ligase ligand-linker conjugate (E3 Ligase Ligand-Linker Conjugates) that incorporates the Thalidomide (Thalidomide (HY-14658)) based cereblon ligand and a linker used in PROTAC technology.In Vitro:PROTACs contain two different ligands connected by a linker; one is a ligand for an E3 ubiquitin ligase and the other is for the target protein. PROTACs exploit the intracellular ubiquitin-proteasome system to selectively degrade target proteins[2].