While HDAC4 is normally located in the cytoplasm, the nuclear accumulation of HDAC4 was observed in dopaminergic neurons overexpressing A53T mutant α-synuclein treated with MPP+/MPTP in vitro and in vivo, indicating that HDAC4 can be a crucial player in the pathology of PD [28]. Here, HDAC4 is linked to Parkinson disease.