Polymorphisms and mutations in the NOD1 and NOD2 genes are associated with high levels of IgE in AD patients and are relevant factors indicating susceptibility to atopy.96, 97 Similarly, polymorphisms in the NLRC4 gene, which also codes for an NLR, are associated with AD;97 however, functional studies on the role of this receptor in the pathogenesis of the disease are still scarce. Here, NOD2 is linked to Alzheimer disease.