XRCC1 and lung cancer: Variant genotypes of XRCC1 399 genetic polymorphism were more likely to associate with lower rates of OS and higher risks of death for advanced lung cancer patients (GlnGln vs. ArgArg: HR = 1.14, 95% CI, 0.75–1.75, P = 0.533, Fig. 3B; GlnGln vs. GlnArg: HR = 1.42, 95% CI, 1.01–2.00, P = 0.043, Table 4).