IL6 and Alzheimer disease: Dysregulation of IL-6 has been implicated in the modulation of various cognitive functions (Donzis and Tronson, 2014) and previous meta-analyses have reported associations between upregulated peripheral IL-6 with Alzheimer's disease (AD) (Swardfager et al., 2010; Lai et al., 2017) and postoperative cognitive dysfunction (Peng et al., 2013).