Thalidomide-NH-C6-NH-Boc is a synthesized E3 ligase ligand-linker conjugate that incorporates the Thalidomide based cereblon ligand and a linker used for MI-389 (compound 22)?synthesis. MI-389 is a potent phthalimide PROTAC degrader based on the multi-targeted receptor tyrosine kinase inhibitor sunitinib (HY-10255A).In Vitro: MI-389 (0-1 μM; 72 hours) decreases cell growth with an EC50 value of 21.3 nM, which is comparable to the cellular potency of sunitinib (EC50=17.3 nM).MI-389 (0-500 nM; 72 hours) leads to GSPT1 destabilization fastly as a dosepdependent manner. It shows a complete GSPT1 depletion at 100 nM.