Thalidomide-O-amido-C8-NH2 is a degron-linker (refer to Compound DL7-TL). The PROTAC linker is bound lo at least one targeting ligand. Degron-linker-targeting ligand, wherein the linker is covalently bound lo at least one degron and at least one targeting ligand, the degron is a compound capable of binding to an ubiquitin ligase such as an E3 ubiquitin ligase (e g, cereblon), and the targeting ligand is capable of binding to the targeted protein (s)[1].