Inhibition of histone deacetylase (HDAC) enzymes by compounds such as trichostatin A can have wide ranging effects in cancer, cell differentiation, and other aspects of gene expression regulation. BML-210 is a small molecule inhibitor of HDAC with an IC50 value of 5-10 uM when tested in HeLa cell nuclear extracts. BML-210 also inhibits the deacetylation of the transcription factor FOXO3 by mammalian SIRT1 in cells oxidatively stressed by hydrogen peroxide.