Patients with homozygous mutant variants (Gln/Gln) of XPD at codon 751 were found significantly associated with lung cancer risk when compared to the control (OR=3.58; 95% CI=1.58-8.09; p=0.002), whereas no significant association was found with heterozygous mutant variants (Lys/Gln) (OR=1.10; 95% CI=0.72-1.68; p=0.745) when Lys/Lys was considered as a reference group. The gene discussed is ERCC2; the disease is lung cancer.