The characteristics of the 26 eligible studies, including year of publication, ethnicity of studied populations, site of cancer, method of genotyping, source of controls, matching criteria, adjusted variables, cases and controls with different genotypes, HWE in controls, and MAF in controls for the XRCC1 Arg194Trp, Arg399Gln, and Arg280His polymorphisms are listed in Tables 1–3 respectively. The gene discussed is XRCC1; the disease is cancer.