Elevated DAT activity has been associated with cell death in vitro [30,50,51,52] and experimental Parkinsonism in vivo [30] due to facilitation of toxin (e.g., MPTP) entry and/or buildup of cytosolic DA resulting in the production of toxic species and oxidative stress [30,50,51,53]. Here, SLC6A3 is linked to Parkinson disease.