CTLA-4 rs231775 polymorphism appears to decrease cancer risk in overall genetic models (G-allele vs. A-allele, OR = 0.94, 95%CI = 0.90-1.00, Pheterogeneity< 0.001, P = 0.037; GG vs. AA, OR = 0.86, 95%CI = 0.76-0.96, Pheterogeneity< 0.001, P = 0.010; GG vs. GA+AA, OR = 0.88, 95%CI = 0.82-0.94, Pheterogeneity< 0.001, P < 0.001). This evidence concerns the gene CTLA4 and cancer.