IL6 and Alzheimer disease: Similarly, a few studies reported association of inflammatory markers, C-reactive protein (CRP), IL-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) with either ACD or AD risk [27, 28], whereas others indicated no association with CRP [29–31], IL-1β [31], IL-6 [19, 31], and TNF-α [31].