MW: 259.26. Clinically, lenalidomide has proven to be effective in the treatment of multiple myeloma and other B cell diseases. It has the ability to selectively bind and ubiquitinate two lymphoid transcription factors, IKZF1 and IKZF2, via the CRBN-CRL4 ubiquitin ligase. This ultimately leads to the degradation of IKZF1 and IKZF2, which are both essential in myeloma cell survival.