We observed a wide variation of the Cys allele frequencies of control resources in Asian (0.52) and Caucasian (0.24) population that were very close to that obtained from the HapMap Project (0.50 for CHB and 0.22 for CEU), and this different allele frequency might account for the discrepancies between the hOGG1 Ser326Cys polymorphism and breast cancer susceptibility among different ethnicity. The gene discussed is OGG1; the disease is breast cancer.