Toll-like receptor 4 (TLR4), is a member of TLR family that recognizes bacterial lipopolysaccharide (LPS) and plays a critical role in the pathogenesis of various neurodegenerative disease including Parkinson’s Disease (Campolo et al., 2019), Alzheimer’s disease (Walter et al., 2007), amyotrophic lateral sclerosis (Lee et al., 2015) and HIV-associated neuroinflammation (Hernandez et al., 2012). Here, TLR4 is linked to Alzheimer disease.