APEX1 and cancer: To understand the underlying molecular mechanism of the observed association of the APEX1-148 variant genotypes (Glu/Glu and Asp/Glu) with lower levels of BPDE-induced DNA adducts and decreased risk of cancer, we further assessed the effect of the APEX1 Asp148 Glu polymorphism on APEX1 mRNA levels using the APEX1 mRNA expression data in EBV-transformed lymphoblastoid cell lines derived from 270 HapMap individuals and available genotyping data from the same individuals.