APP and Alzheimer disease: To investigate the relationship between the concentrations of AEP-derived APP fragments and Aβ, we developed an enzyme-linked immunosorbent assay (ELISA) using our cleavage-stie-specific antibodies and found that the concentrations of AEP-derived APP586–695 correlated with Aβ in AD and age-matched control brains (Supplementary Fig. 8f).