. . . . . . . . . . . . "[The dopamine receptor D4 gene (DRD4) is associated with heroin dependence; one of its polymorphisms is a C/T variation 521 bp upstream to the gene (-521C/T).]. Sentence from MEDLINE/PubMed, a database of the U.S. National Library of Medicine."@en . . . . . "2015-02-21"^^ . . "Gene-disease associations inferred from text-mining the literature."@en . "DisGeNET evidence - LITERATURE"@en . "2016-05-13T12:42:48+02:00"^^ . . . . . . . . . . . "v4.0.0.0" . "v4.0.0" .