PDE10A and Huntington disease: PDE10A has been proposed as a novel therapeutic target for diseases of the basal ganglia but inhibitors of this enzyme failed to show efficacy in clinical trials for both HD and schizophrenia (https://www.clinicaltrials.gov/: NCT02197130, NCT02074410, NCT02342548, NCT01806896, NCT01939548, NCT01175135).