XRCC1 and squamous cell carcinoma: On the other hand, individuals homozygous for the XRCC1 399Gln allele presented no risk of developing lung cancer (OR = 0.87; 95%CI = 0.57–1.31) except for individuals carriers of 399Gln/Gln genotype and without family history of cancer (OR = 0.57; 95%CI = 0.33–0.98) and no association was found between XRCC3 Thr241Met polymorphism and lung cancer risk (OR = 0.92; 95%CI = 0.56–1.50), except for the 241Met/Met genotype and squamous cell carcinoma risk (OR = 0.47; 95%CI = 0.23–1.00).