Carriers of TTC12-rs10502172[G] had 1.64 increased odds (95%CI: 1.10–2.45) of being ex-smokers than non-carriers. In contrast, carriers of CHRNA3-rs1051730[A] were more likely to be persistent-smokers [OR(95%CI):1.58(1.23–2.04)] and late onset-smokers [OR(95%CI):1.16(1.01–1.34)] than non-carriers (Table 4).