C3 and Alzheimer disease: Taken together, we conclude that some consistent biomarkers, such as TNF‐α, NfL, ICAM1, M‐CSF, CRP, factor VII, MCP, adiponectin, tenascin C, PPP, FABP, TLSP, ApoA4, CO9, ApoC3, VCAM1, complement C3, and β2M, have been identified in both the serum and plasma of AD cohorts and could serve as reliable candidate biomarkers for the prediction of AD.