SLC6A3 and Parkinson disease: Using a recently-developed PET radiotracer, 18F-(E)-N-(3-iodoprop-2-enyl)-2β-carbofluoroethoxy-3β-(4′-methyl-phenyl)nortropane (18F-FE-PE2I), reduction in DAT in the striatum and SN was replicated in PD patients versus controls.