Thalidomide and its structural analogs lenalidomide and pomalidomide promote the ubiquitination-mediated degradation of two essential transcription factors, IKZF1 (Ikaros) and IKZF3 (Aiolos), by directly recruiting them to CRBN, thereby inhibiting the proliferation of myeloma cells. Here, IKZF3 is linked to plasma cell myeloma.