TNF and Alzheimer disease: In addition, several strategies suggest that Porphyromonas gingivalis causes an inflammatory response in the liver through the increased expression of pro-inflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6), as well as fat storage-inducing transmembrane protein 2 (Fitm2) and perilipin 2 (Plin2), associated with lipid droplet formation, which subsequently increases neuroinflammation and causes neurodegenerative changes and AD [12,19,20].