The interpretation of the detected CYP2A7 association is challenging, as the possible role of CYP2A7 in nicotine metabolism is unknown. Our top SNP in CYP2A7 (rs28602288) is located within a predicted promoter region. It is plausible that the association between rs28602288 and NMR reflects the regulation of CYP2A6*12 (a hybrid allele of CYP2A6 and CYP2A7) or similar constructs, such as the one generated by the 32 kb deletion tagged by esv2663194, rather than implies a role for CYP2A7 in nicotine clearance. Rs28602288 is in LD with all of the independent variants (D’ = 0.67–1.00).
