Allele frequencies, genotype frequencies, and OR and 95% CI for association between ERCC4 polymorphisms and SCCHN risk.

aCochran-Armitage trend test for genotype distributions under an additive genetic model between cases and controls.bChi square test for allele and genotype distributions under a recessive genetic model between cases and controls.cAdjusted by age, gender, smoking status and alcohol status in logistic regression models.dOne case and four controls genotyping were failed for rs1799798.