TLR2 polymorphisms have been investigated in the field of atopy and allergic diseases (5,6,7,16,17,18,26,27,28,29,30), involving AD (5,6,7,16,17,18,28,30), but the results of published association studies on TLR2 SNPs and the risk of AD are contradictory. This evidence concerns the gene TLR2 and Alzheimer disease.