Journal of Experimental & Clinical Cancer Research 2009, 28:153 http://www.jeccr.com/content/28/1/153 the particularity of exposure to carcinogen in different populations and genetic differences of study subjects play important roles in it. In addition, the ERCC2 751 poly- morphism may function through haplotype but not through genetic exon to affect protein activity. Is this appropriate for other SNPs in ERCC2 and ERCC1? The exact effects and mechanisms of these polymorphisms on lung cancer need further studies to elucidate. As reported in previous study [25], the ERCC2 751C, 312A and ERCC1 118T alleles have been found to be in linkage disequilibrium. The exploratory haplotype analy- ses in the present study revealed the associations between the 751A-312G-118T and 751C-312G-118C haplotypes and the increased risk of lung adenocarcinoma in non- smoking females. The result showed that none of the ana- lyzed haplotypes included the variant allele of ERCC2 312 polymorphism. Some European studies found that ERCC2 312 and 751 polymorphisms are closely linked and their effects are difficult to be separated. Our study indicated that ERCC2 751 polymorphism may indeed be of functional importance for lung adenocarcinoma among non-smoking female population. Because it is just a statistical estimation, further studies are required to con- firm its biological validity. Few molecular epidemiological studies of lung adenocar- cinoma have been conducted thus far. This study is one of the largest studies among non-smoking female popula- tion to evaluate the correlation between NER gene poly- morphisms and risk of lung adenocarcinoma, and also the gene-environment interaction in the development of lung adenocarcinoma. The strength of this study is its low rate of misclassification of outcome, as all of the cases were pathologically confirmed. In summary, our study sheds light on the relationship between polymorphisms in the DNA repair gene ERCC2 and ERCC1 with environmental risk factors and suscepti- bility to lung adenocarcinoma in nonsmoking females in northeast China. Our results show that the ERCC2 751C allele or the haplotypes encompassing the variant allele are associated with risk of lung adenocarcinoma in Chi- nese nonsmoking female population. While the func- tional interpretation remains elusive, additional larger studies are needed to validate our findings. Conclusion The results of the present study indicate that ERCC2 751 polymorphism (rs13181) might be a genetic risk modifier for lung adenocarcinoma in non-smoking females in China. Competing interests The authors declare that they have no competing interests. Authors' contributions ZY carried out the molecular epidemiological studies, par- ticipated in SNP detection and statistical analysis and drafted the manuscript. 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