In an in vivo study, the availability of the dopamine transporter by using [11C]CFT was reduced in the putamen after 1 h of strenuous walking in normal subjects but not in PD patients, indicating that this abnormal activation might be linked to the pathophysiology of the parkinsonian gait (Ouchi et al., 2001). The gene discussed is SLC6A3; the disease is Parkinson disease.