They demonstrated a decrease in S1R binding potential (BP) but only in the most affected anterior putamen (as assessed by 11C-CFT for dopamine transporter and 11C-raclopride for D2 receptor PET imaging) but interestingly did not detect differences between controls and PD patients when measuring 11C-SA4503 in the anterior putamen bilaterally 17. This evidence concerns the gene SLC6A3 and Parkinson disease.