Strategies to monitor dopamine nerve terminals in vivo in PD brains include striatal uptake of (18)fluorodopa or (11)C-beta-CFT [2-beta-carbomethoxy-3beta-(4-fluorophenyl) tropane] revealed, by positron emission tomography (PET) [1, 2, 3] and beta-CIT or (123)I in single-photon emission computerized tomography (SPECT), to show distribution of dopamine transporters (DAT), among other tracer-DAT ligands [4, 5]. This evidence concerns the gene SLC6A3 and Parkinson disease.