After bone marrow mesenchymal stem cell (BMSC) transplantation in a rat model, improvement of symptoms and recovery of DAT binding on [18F]FP-CIT PET were confirmed [155].As it is a neurodegenerative disease with the second highest prevalence after Alzheimer’s, numerous studies are being conducted on treating PD, and [18F]FP-CIT PET is expected to serve as a valuable biomarker for evaluating the response of these therapeutic strategies. Here, SLC6A3 is linked to Parkinson disease.