In line with previous studies [12], they found that A2A receptor binding was higher in the caudate and putamen of PD patients with L-DOPA-induced dyskinesias, with respect to both PD patients without L-DOPA-induced dyskinesias and controls, thereby lending further support to the view that A2A antagonists may prove beneficial in the management of motor complications associated with L-DOPA treatment. This evidence concerns the gene IGKV2D-29 and drug-induced dyskinesia.