“…Previous studies reported that the human X-ray repair complementing group 1 (XRCC1) gene is one of the most important candidate genes for influencing susceptibility to lung cancer (Hao et al, 2006;Giachino et al, 2007;López-Cima et al, 2007;Sreeja et al, 2008;Chang et al, 2009;Kalikaki et al, 2009;Wang et al, 2009;Yin et al, 2009a,b;Butkiewicz et al, 2011;Li et al, 2011;Qian et al, 2011;Chen et al, 2012;Cui et al, 2012;Guo et al, 2013). The potential associations between lung cancer and multiple genetic variants of XRCC1 in different populations have been reported (Hao et al, 2006;Giachino et al, 2007;López-Cima et al, 2007;Improta et al, 2008;Sreeja et al, 2008;Chang et al, 2009;Kalikaki et al, 2009;Yin et al, 2009a,b;Butkiewicz et al, 2011;Qian et al, 2011;Cui et al, 2012;Guo et al, 2013). Several genetic variants, including arginine (Arg) 194 tryptophan (Trp), Arg 280 histidine (His) and Arg399 glutamine (Gln), were significantly associated with the susceptibility to lung cancer (Giachino et al, 2007;López-Cima et al, 2007;Sreeja et al, 2008;Kalikaki et al, 2009;Yin et al, 2009a,b;Butkiewicz et al, 2011;Qian et al, 2011;Guo et al, 2013).…”