XRCC4 and central nervous system cancer: In comparison with the reference combination of LIG4 rs1805388 CC and XRCC4 rs1805377 AA, the combination of the LIG4 rs1805388 CT+TT genotype together with XRCC4 rs1805377 AG+GG genotype was found to be significantly associated with glioma (adjusted OR, 2.22; 95% CI, 1.49-3.30).