We found that, in the overall population, there is a significant association between IL-18 -607 C/A polymorphism and prostate cancer risk using a recessive (CC versus CA/AA: OR = 0.20, 95% CI = 0.15-0.27, P = 0.000, Figure 5) or dominant (CC/CA versus AA:OR = 0.42, 95% CI = 0.30–0.57, P = 0.000, Figure 6) model. This evidence concerns the gene IL18 and prostate cancer.