CLPTM1L and chronic obstructive pulmonary disease: The results in this study suggest that the rs1052486 SNP on the 6p21 locus (BAT3) confers susceptibility to lung cancer in smokers with pre-existing COPD and that, the rs402710 SNP on the 5p15 locus (CRR9/TERT) and the rs2808630 SNP on the 1q23 locus (CRP) confer susceptibility to lung cancer in those with no pre-existing COPD.