An increased expression of TLR2, TLR4, TLR5, TLR7, TLR9 and the TLR co-receptor CD14 has been shown in microglia cells situated around senile plaques in post-mortem brain of AD patients and related mouse models (Liu et al., 2005; Walter et al., 2007; Jana et al., 2008; Letiembre et al., 2009). This evidence concerns the gene TLR9 and Alzheimer disease.