IKZF1 and plasma cell myeloma: IMiDs target CUL4-RBX1-DDB1-CRBN (CRL4CRBN) E3 ligase to induce the ubiquitination and proteasomal degradation of Ikaros family zinc finger proteins, Ikaros (IKZF1) and Aiolos (IKZF3) which are the lymphoid transcription factors essential for myeloma cell survival [33–35].