Previous studies have shown that the pharmacologic modulation of mGlus can ameliorate motor abnormalities in experimental models of PD [27]–[28], and blockage of mGlu5 has shown a beneficial antidyskinetic effect in L-dopa-treated 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine ( MPTP) ) monkeys [29]. The gene discussed is GRM5; the disease is Parkinson disease.