SV2A and Alzheimer disease: Compared with the NCs, SV2A levels were lower in all the hippocampal subfields of AD patients, namely, the DG (P = 0.0017), CA2/3 (P = 0.0462), CA1 (P = 0.0024), and subiculum (P = 0.0462), as well as in the entorhinal cortex (P = 0.0462) (Figs. 3a–f and 4a, Fig. S11).