Interestingly, a relationship between A2AR and LIDs has been established, thus an increased striatal A2AR density has been reported in experimental animal models of LID (Zeng et al., 2000) and in PD patients with dyskinesia (Calon et al., 2004; Ramlackhansingh et al., 2011). This evidence concerns the gene ADORA2A and Dyskinesia.