Lenalidomide-Br (Compound 41) is an analog of cereblon (CRBN) ligand Lenalidomide for E3 ubiquitin ligase, and is used in the recruitment of CRBN protein. Lenalidomide-Br can be connected to the ligand for protein by a linker to form PROTACs, such as the PROTAC STAT3 degrader SD-36 (HY-129602)[2].In Vitro: Lenalidomide-Br can be connected to the ligand for protein by a linker to form PROTACs. PROTACs are inducers of ubiquitination-mediated degradation of cancer-promoting proteins[2].