Since LPS and Aβ are both agonists for the TLR4/CD14 receptor (Lehnardt et al., 2002; Vollmar et al., 2010; Scott et al., 2017), this could set up a vicious cycle where LPS acts on the TLR4/CD14 receptor which increases Aβ which in turn provides positive feedback on the TLR4/CD14 receptor to produce progressive injury in AD brain. This evidence concerns the gene TLR4 and Alzheimer disease.