Thalidomide-NH-CH2-COOH is the Thalidomide-based cereblon ligand used in the recruitment of CRBN protein. Thalidomide-NH-CH2-COOH can be connected to the ligand for protein by a linker to form PROTACs, such as THAL-SNS-032 (HY-123937).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.