SYP and Alzheimer disease: Notably, we observed significant decreases in proteins at the late stage of AD (AD Braak stages V–VI), including adaptor-related protein complex 2 subunit beta 1 (AP2B1), complexin-2 (CPLX2), GAP43, SNAP25, gamma-synuclein, SV2A, syntaxin 1B, SYP, SYT1, tubulin beta 3 class III (TUBB3) and 14-3-3ζ (Fig. 2a–l).