APP and Alzheimer disease: Lower levels of 7 of these proteins (NECTIN, NCSTN, NCSTN, NPTXR, CNTN2, NRXN1, APP) were associated with worse immediate recall in non-AD MCI (NECTIN1, NCSTN, NCSTN, NPTXR, NRXN1 and APP; Fig. 4).