The longstanding “dopamine hypothesis of schizophrenia” is based primarily on 2 facts: (1) all antipsychotics currently available to treat the positive symptoms of schizophrenia possess dopamine D2 receptor blocking activity and (2) hyperactive dopamine release in subcortical limbic brain regions, especially in the nucleus accumbens/striatum, has been consistently observed in patients with schizophrenia [94, 95]. The gene discussed is DRD2; the disease is schizophrenia.