However, three recent studies reported that the TS 3'-UTR ins6/ins6 and/or del6/ins6 +ins6/ins6 genotypes were associated with a significantly increased risk for gastric cancer, SCCNH and lung cancer [19,23,26], while some other studies did not observe any associations between this polymorphism and cancer risk [29,30,34]. This evidence concerns the gene TYMS and lung carcinoma.