NRGN and Alzheimer disease: Interestingly, we found that both the Aβ 42/Ng and Aβ 42/α-Syn values are influenced by the presence of the AD-related PET pattern; moreover, the Ng concentration and Aβ 42/Ng value were influenced by the presence of the ApoE4 genotype and pathological values of AD-core biomarkers.