TLR4 and Alzheimer disease: The TLR4 can recognize pathogen-associated molecular patterns (PAMPs) (e.g., bacteria, virus, or fungi) as well as damage-associated molecular patterns (DAMPs) released after tissue damage [119], and its expression, together with the production of pro-inflammatory cytokines, has been found to be increased in the frontal cortex of AD patients [120] and in the AD-like APP/PS1 mouse model with microglial cell activation, neuronal loss, and exacerbated cognitive deficits [121].