In addition, although the severity of cardinal motor symptoms, assessed by the motor section of the unified Parkinson’s disease rating scale (UPDRS), is considered a good predictor of the neuronal loss observed in the substantia nigra (SN) [77], several studies attempting to correlate DAT in vivo imaging outcomes and neuropathological findings in humans have provided conflicting results [91]. Here, SLC6A3 is linked to Parkinson disease.