Although we did not see significant differences in plasma cystatin C levels between AAA patients and control patients (Table 1), and plasma cystatin C did not predict AAA (Figure 1), logistic regression analysis did demonstrate a significant correlation of plasma cystatin C with AAA, and cystatin C served as an independent AAA risk factor (OR  = 0.356, P<0.001) (Table 2). The gene discussed is CST3; the disease is triple-A syndrome.