IL-6 may be both proinflammatory and anti-inflammatory and is elevated in the plasma, CSF, and brain of AD patients (Ershler and Keller, 2000; Licastro et al., 2000, 2003; Shibata et al., 2002; Baranowska-Bik et al., 2008; Galimberti et al., 2008). Here, IL6 is linked to Alzheimer disease.