They are wellcharacterized for their interactions with other aminergic receptors,, and for example their D2R-mediated side-effect profiles includehallucinations, delusions, and illusions., Also of consequence are many antipsychotic drugs serving as D2Rantagonists (e.g., ziprasidone and paliperidone) that possess D1Rantagonism with Parkinsonism side effects.,, For these reasons alone, drug discoverystrategies that emphasize D1R selectivity have become a high priorityfor designing next-generation PD therapies. This evidence concerns the gene DRD2 and Parkinson disease.