Altered D3R signaling is associated with a number ofpathological conditions, including substance use disorder, Parkinson’sdisease (PD), schizophrenia, depression, and restless leg syndrome.10−17 Each of these conditions may benefit from pharmacological manipulationof D3R signaling, and selective D3R ligandsmay represent important pharmacological tools that might provide furtherinformation toward the D3R (patho)physiological role andthat lack motor side effects associated with D2R blockade.17−20. This evidence concerns the gene DRD2 and schizophrenia.