The results of multivariate logistic regression analysis showed that high levels of D-dimer and high levels of cystatin C were independent risk factors for intracranial aneurysm (D-dimer: OR = 15.10, 95% CI: 3.08–74.02, P < 0.01; cystatin C: OR = 15.10, 95% CI: 3.08–74.02, P < 0.01) (Table 4). The gene discussed is CST3; the disease is Dilatation of the cerebral artery.