As expected, the most predictive proteins spanned a wide swath of AD biology, capturing synaptic (NPTX2, PNOC, YWHAZ, YWHAE, PPP3CA), presynaptic (UCHL1), ECM (ADAMTS1, ADAMTSL3), neuronal-signaling (BMP7), neuroinflammatory (RELT, CTSS, LILRB4), and metabolic (FABP3, GAA, SPINT1, GNPTG, FAM3B) processes, highlighting that progression is foreshadowed by coordinated disruption across multiple molecular systems (Fig. 4d). Here, PPP3CA is linked to Alzheimer disease.