Although far from conclusive, a recent report of a single-center, open-label clinical pilot study involving patients with mild-to-severe AD who received semi-weekly perispinal infusion of the anti-TNF biologic etanercept for six months claimed detectable improvement of cognitive performance in patients who received etanercept compared to those that received placebo, raising the interesting possibility that modulation of TNF signaling peripherally or centrally may have effects on cognitive performance in patients with AD [177]. Here, TNF is linked to Alzheimer disease.