Whereas no significant changes in diameter ratios were found in sham groups (3 weeks: WT-SHAM: 0.96 ± 0.22, TNC KO-SHAM: 0.92 ± 0.08, n.s.; 10 weeks: WT-SHAM: 0.94 ± 0.10, TNC KO-SHAM: 1.05 ± 0.16, n.s.), TNC KO mice with AAA showed a significantly lower diameter ratio compared to the WT group 3 weeks (TNC KO: 1.39 ± 0.25, WT: 1.67 ± 0.22, P < 0.05, Fig. 3A) and 10 weeks (TNC KO: 1.51 ± 0.47, WT: 1.98 ± 0.55, P < 0.05, Fig. 3B) after AAA induction, respectively. The gene discussed is TNC; the disease is triple-A syndrome.