In Table 5, we also presented the association results for NCK2 and comorbidity of substance dependence. The most significant signal in NCK2 was observed for SNP rs2377339 in men of African-origin with P = 3.65 × 10−8 in adjusted association test and P = 2.03 × 10−8 in unadjusted association test. P values of SNPs in NCK2 for other ethnicity by gender groups were far from the genome-wide significance level and, hence, are omitted here.
