Previous studies have reported that the dysfunction ofVMAT2 can evoke cytoplasmic dopamine accumulation, which leads todopaminergic neuron death.6 Other studieshave shown that protein expression levels of VMAT2 were significantlyreduced in PD patients7 and that an increasedVMAT2 level or function might protect against the development of PD.8,9 Therefore, striatal VMAT2 is considered as a presynaptic markerof dopamine terminal loss in PD.10 The gene discussed is SLC18A2; the disease is Parkinson disease.