NRGN and Alzheimer disease: Specifically, compared with HC, Aβ and tau-related proteins (Aβ42, Aβ42/40, p-S396-tau, p-Tau181) increased, synaptic-related proteins (neurogranin, synaptotagmin, synaptotagmin 1, synaptopodin, synaptophysin, NMDAR2A) decreased significantly in patients with AD.