Significant associations between -607C/A polymorphisms in IL-18 gene promoter and cancer risk were observed in the heterozygous model (CA vs CC:OR =1.221, 95% CI: 1.096, 1.360; Pheterogeneity=0.219, Figure 2) and the dominant model (AA/CA vs. CC:OR =1.203, 95% CI: 1.057, 1.369; Pheterogeneity=0.064, Figure 3) in this meta-analysis. The gene discussed is IL18; the disease is cancer.