Among the mediators involved in the systemic immune response regulation, including transcriptional factors, cytokines, chemokines, complements, coagulation factors, enzymes, various peptides and lipids [127], interleukins (IL-1, IL-4, IL-6 and IL-10), cytokine I-309, interferon-γ, and tumor necrosis factor α (TNF-α) are particularly important biomarkers for the early diagnosis of AD [105]. Here, TNF is linked to Alzheimer disease.