Association study of polymorphisms in the promoter region of DRD4 with schizophrenia , depression , and heroin addiction .
O O O O O O O O O B-GeneOrGeneProduct O B-DiseaseOrPhenotypicFeature O B-DiseaseOrPhenotypicFeature O O B-DiseaseOrPhenotypicFeature I-DiseaseOrPhenotypicFeature O