XRCC1 and glioma: The overall data failed to indicate a significant association of the XRCC1 Arg194Trp polymorphism with glioma risk [Trp vs. Arg: odds ratio (OR) = 1.01, 95% confidence interval (95% CI) = 0.77–1.33; Trp/Trp vs. Arg/Arg: OR = 1.56, 95% CI = 0.96–2.54; dominant model: OR = 0.98, 95% CI = 0.74–1.31; recessive model: OR = 1.48, 95% CI = 0.92–2.38].