Correlation analysis between serum IL-18 level and aortic calcium content of all the rats in three groups at the 6th month after surgery (Figure 7) showed that serum IL-18 level was positively correlated with aortic calcium content (r = 0.934, p < 0.001), indicating that with the increase of serum IL-18 level, the degree of aortic calcification in rats became serious. This evidence concerns the gene IL18 and calcification.