After adjusting hypertension, high TLR4 expression in situ was independently associated with an increased risk of large AAA (OR = 6.211, 95%CI = 1.226–31.480, P = 0.027), while high MMP9 expression was significantly related to the presence of thrombus within AAA after the adjustment for smoking and hypertension (OR = 5.494, 95%CI = 1.181–25.562, P = 0.030) (Table 5). Here, MMP9 is linked to triple-A syndrome.