Strikingly, upregulated levels of IL-6 and TNF-α in serum of patients with depression or Alzheimer’s disease were identified (Dowlati et al., 2010; Gaur and Agnihotri, 2015; Ng et al., 2018), suggesting a role of pro-inflammatory cytokines in promoting cognitive disorders. This evidence concerns the gene IL6 and early-onset autosomal dominant Alzheimer disease.