{{Rsnum
|rsid=35286281
|Chromosome=20
|Orientation=plus
|Gene=PDYN
|position=1975953
|Assembly=GRCh37
|GenomeBuild=37.1
|dbSNPBuild=132
|Status=Deleted
}}{{PMID Auto
|PMID=21382455
|Title=Association between heroin dependence and prodynorphin gene polymorphisms
}}{{PMID|18923396|OA=1
}} A functional haplotype implicated in vulnerability to develop cocaine dependence is associated with reduced PDYN expression in human brain.