Nicotine dependent subjects were selected from the COGEND collection628 using the results of the Fagerström test of nicotine dependence29 and the homozygous presence of the minor allele (AA) of rs16969968 as well as the presence of homozygous major alleles for other SNPs known to affect addiction behaviors and/or nAChR function: rs880395 (GG), rs8192475 (GG), rs12914008 (GG), and rs56218866 (TT) (Supplemental Table 1). Non-nicotine dependent control subjects who smoked came from the same collection, and were homozygous for the major allele of rs16969968 (GG) but matched at the other SNPs. One male and two females were selected for each group. Primary lymphocytes were processed for reprogramming as described previously24. Pluripotency was confirmed by immunocytochemistry (ICC) for Oct4 and TRA-1-60 (Fig. 1A,B), by embryoid body formation followed by detection of three germ layers by immunocytochemistry (not shown), and by gene expression studies, including the PluriTest algorithm30 (Supplemental Table 2). All tests were positive for pluripotency.
