HDAC4 (Histone deacetylase 4) is a member of the histone deacetylase family. Histones play a critical role in transcriptional regulation, cell cycle progression and developmental events. Histone acetylation/deacetylation alters chromosome structure and affects transcription factor access to DNA. HDAC4 belongs to class II of the histone deacetylase/acuc/apha family. It possesses histone deacetylase activity and represses transcription when tethered to a promoter. This protein does not bind DNA directly, but through transcription factors MEF2C and MEF2D. It seems to interact in a multiprotein comple, Xenopus/Amphibian, with RbAp48 and HDAC3.