TLR2 and Alzheimer disease: IL-12 and IL-18 are inducers for IFN-γ expression [20], however, the mRNA expression IL-12 and IL-18 did not display noticeable difference from PBMCs triggered by TLR2 ligands in AD patients compared with healthy controls, nor did TLR2-ligands stimulated the release of the two cytokines in both groups.