TNF and Alzheimer disease: A meta-analysis conducted by Swardfager et al., found elevated levels of pro-inflammatory cytokines like interleukin-1 beta (IL-1β,) tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and transforming growth factor-beta (TGF-β) in blood samples of AD patients and elevated levels of TGF-β in cerebrospinal fluid (CSF) of AD compared to healthy controls [15].