The DNA methylation rate of the NPTX2 gene at four CpG regions and its relationship between thymoma/TC and normal thymic tissues are shown in Figure 3A. The DNA methylation rate did not significantly differ between thymoma and normal thymic tissues (left side, the paired t-test, p = 0.378), but was significantly higher in TC than in normal thymic tissues (right side, the paired t-test, p < 0.001). This evidence concerns the gene NPTX2 and thymoma.