TNF and Alzheimer disease: In most of the studies published, these AD dogs showed high levels of one or more of these proinflammatory cytokines: IFN-γ [44,45,47,53,54,55,63,64,65], TNF-α [53,54,63], IL-2 [31,63], IL-18 [63,65,66], IL-6 [65,66], IL-15, and IL-7 [65].