SV2A and Alzheimer disease: Initially, CSF SV2A demonstrated significant diagnostic ability for aMCI (AUC = 78.8%, 95% CI = 0.647–0.891, sensitivity = 100.00%) (Fig. 2h) and differential diagnosis of aMCI from AD (AUC = 86.8%, 95% CI = 0.756–0.942) (Fig. 2j).