Schematic model of cereblon (CRBN) binding and differential substrates resulting in pleiotropic activity. The boxes outlined in blue represent the common glutarimide moiety responsible for CRBN binding, and the circle outlined in red highlights the structural difference from the phthalimide moiety. CC-122 shares the same molecular target, CRBN, as lenalidomide, pomalidomide, and thalidomide; however, differential substrate profiles and/or kinetics of substrate degradation can manifest different biological effects that are cell-type dependent. DDB1, DNA damage-binding protein 1; NK, natural killer. Figure courtesy of Celgene Corporation.