To our knowledge, no SNPs in the SPOCK2 gene, which encodes a protein that forms part of the extracellular matrix, have been reported previously in association with smoking behaviors or smoking-related cancer phenotypes. Variants at the SPOCK2 locus have been linked to bronchopulmonary dysplasia, a respiratory condition observed in premature infants48 that has been linked to intrauterine smoke exposure.49 These variants are weakly correlated with the SNPs identified at this locus for AOI in Europeans (r2<0.25 in CEU), but are not correlated in the African ancestry populations (r2=0). The top SNP associated with SC (rs3813637) is located at 1q25 in the C1orf49 gene. This locus has been linked to late-onset Alzheimer's disease, but genetic variation at this locus has not been reported in association with smoking behavior.50 We are not aware of any smoking-related, other behavioral or pathological phenotypes associated with the variants we detected at 1q44 (C1orf100) and 15q12 (LOC503519) or CTCT1 for CPD.
