Comparison of the enriched process networks between plasma and brain proteins. Up/downregulated plasma proteins from 18 AD patients were compared to those from two AD brain regions (SF and IF) of five AD patients (p < 0.05). (SF, superior frontal cortex; IF, inferior frontal cortex). Plasma proteins enriched in the inflammation/complement system include CRP, C4a, C8γ, MBL2, Ficolin/H-Ficolin, C9, and FHR-3; IL-6 signal components include ORM1, SAA2, A2M, CRP, APCS, HP, ACT, SAA4, and SAA1; immune response/phagocytosis system include SAA2, CRP, HDL proteins, APOC3, MBL2; blood coagulation components include SAA2, A2M, Coagulation factor XII, Protein C inhibitor, SAA1, and Coagulation factor XIII A.