In further stratified analyses, CTLA-4 +49A/G polymorphism was found to be significantly associated with susceptibility to NSCLC in these models (dominant model: OR=1.404, 95%CI: 1.074-1.836; allele model: OR=1.273, 95%CI: 1.034-1.565; homozygous model: OR=1.553, 95%CI: 1.044-2.310; heterozygous model: OR=1.308, 95%CI: 1.062-1.611). Here, CTLA4 is linked to non-small cell lung carcinoma.