In addition, prolonged treatment of an HD mouse model with vorinostat (or suberoylanilide hydroxamic acid: SAHA), which is an inhibitor of class I HDACs as well as the class IIb enzyme HDAC6, caused a decrease in HDAC4 and HDAC2 levels in the cortex and brain stem without affecting their transcript levels. Here, HDAC4 is linked to Huntington disease.