Evidence for this comes from an acute 11C-raclopride PET tracer displacement study in healthy volunteers (Boileau et al., 2007; 23% displacement) and a chronic PET displacement study with the dopamine transporter selective tracer 11C-RTI32 in Parkinson’s patients (11% displacement; Guttman et al., 2001). Here, SLC6A3 is linked to Parkinson disease.