XRCC1 and lung cancer: In order to resolve this conflict, meta-analysis was performed to examine the association between XRCC1 and XRCC3 polymorphisms and lung cancer risk, by critically reviewing 41 studies on XRCC1 Arg399Gln, 23 studies on Arg194Trp, 16 studies on Arg280His, 5 studies on −77T>C, and 19 studies on XRCC3 T241M.