We show that this HDAC inhibitor is highly efficacious against myeloma cells, inducing apoptosis via its effects on the acetylome, and go on to demonstrate that it is highly synergistic when combined with the aminopeptidase inhibitor tosedostat (CHR-2797) [22], which we have previously shown to have potent anti-myeloma activity in vitro and in vivo [23, 24]. The gene discussed is HDAC9; the disease is plasma cell myeloma.