The relationship in terms of the mRNA expression of the NPTX2 gene between thymoma/TC and the normal thymus is shown in Figure 4A. mRNA expression levels were slightly lower in five thymomas than in the normal thymus (left side, the paired t-test, p = 0.184), and were also slightly lower in six TC than in the normal thymus (the Wilcoxon signed-rank test, p = 0.176). Here, NPTX2 is linked to thymoma.