CRBN and cancer: CRBN and VHL are E3 ligases that are the most widely used substrates for heterobifunctional degraders to induce the ubiquitination and proteasomal degradation of proteins of interest, because they are ubiquitously expressed in cancer cells.[33] Treatment with UBX‐390 induced AR degradation in both the cytosol and nucleus of VCaP cells, suggesting that UBX‐390 can recruit AR to CRBN in the nucleus, even when CRBN is less abundant in the nucleus than in the cytosol.