Post-translational modifications on histones are instrumental in the regulation of gene expression.  One such modification is the acetylation of lysine residues, which is modulated by histone acetyl transferases (HATs) and histone deacetylases (HDACs).  While HDACs mainly modulate histone substrates, they also work on other acetylated targets such as certain transcription factors.  BRD2577 is a structurally novel inhibitor of the HDAC family, with IC50 values ranging from 11µM to 74µM (SMM, fluorescence assay, cell-based acetylation assay).  The small molecule probe BRD2577 can be used to study the biology of the HDAC enzyme family in vitro and in vivo. Kemp et al., Bioorg. Med. Chem. Lett. 21, 2011.