Thalidomide and its analogs lenalidomide and pomalidomide directly bind to the cereblon (CRBN) (7) and subsequently recruit neo-substrates IKZF1/3 to the CRL4CRBN E3 ligase, thereby inducing ubiquitination and degradation of IKZF1/3 and exhibiting an anti-myeloma effect (8, 9). Here, IKZF1 is linked to plasma cell myeloma.