APP and Alzheimer disease: For 7 of these proteins lower levels were associated with worse immediate recall in non-AD MCI (nectin-1 (NECTIN1), nicastrin (NCSTN), CLSTN3, neuronal pentraxin receptor (NPTXR), CNTN2, neurexin-1 (NRXN1), amyloid precursor protein (APP); Figure 4).