TLR2 and Alzheimer disease: For instance, early minor stimulation of microglial TLR2 and TLR4 receptors by their ligands monophosphoryl lipid A (MPL), and Pam3Cys can facilitate microglia to sense/clear soluble Aβ, safeguard synaptic function, and improve AD-related memory deficits in rats (Pourbadie et al., 2018).