Considering the correlation between DM and PD, researchers have employed a molecular imaging probe for VMAT2, the PET radioligand [18F]fluoropropyl-(+)-dihydrotetrabenazine (18F-FP-(+)-DTBZ or 18F-AV-133), as a molecular marker that can be used to objectively analyze dopamine and β cells. This evidence concerns the gene SLC18A2 and Parkinson disease.