SLC6A3 and Parkinson disease: Almost a decade later, studies with dopamine transporter (DAT) radiotracers, mainly [123I]-β-CIT, showed significant differences on the valid distribution and affinity to DAT between healthy controls and parkinsonism secondary to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MTPT) [11].