Preclinical data of the structurally similar HDAC6 inhibitor ricolinostat support enhanced immunomodulation with HDAC6 inhibition (24), and preliminary data from early-phase studies in multiple myeloma showed a favorable tolerability profile of ACY-241 (25) or ricolinostat (in combination with lenalidomide and dexamethasone) (26). Here, HDAC6 is linked to plasma cell myeloma.