Thalidomide 5-fluoride is a thalidomide-based Cereblon ligand used to recruit Cereblon protein. Thalidomide 5-fluoride can be linked to target protein ligands (e.g. IRAK4 ) through a linker to form PROTAC molecules (e.g. PROTAC IRAK4 degrader-1). PROTAC IRAK4 degrader-1 caused <20%, >20-50%, and >50% IRAK4 protein degradation in OCI-LY-10 cells at concentrations of 0.01, 0.1, and 1 μM, respectively .