Using the striatum as our main region of interest (ROI), we sought to determine whether (1) the polymorphisms would reflect on TSPO binding affinity also in PD patients; (2) [18F]-FEPPA VT could differentiate the PD group from the healthy control (HC) group; and (3) the levels of TSPO binding correlate with clinical measures of PD. Here, TSPO is linked to Parkinson disease.