For any novel region having genome-wide significant association with nicotine dependence, we selected SNPs and indels associated at meta-analysis P<5 × 10−5 for follow-up testing across five independent European-ancestry samples: Yale-Penn study,33, 34, 35 Finnish Twin Cohort Study (FTC),36, 37 University of Wisconsin-Transdisciplinary Tobacco Use Research Center (UW-TTURC),12 Genetic Association Information Network (GAIN) GWAS of Schizophrenia and Molecular Genetics of Schizophrenia—nonGAIN Sample.
