The main criterion for system/gene selection was participation in response to more than one drug class and/or drug abuse-related behaviors. The gene set is based on and substantially overlaps with that selected for the large-scale genotyping by the National Institute on Drug Abuse Genetics Consortium (24). Genes (n = 456) were prioritized on a 1 to 5 scale and submitted for SNP selection. We iteratively adjusted our LD-tagging criteria to allow for inclusion of 106 first-priority candidate system genes in our panel for an Illumina 1536 SNP oligonucleotide pool assay.
