Humans with the APOE4 variant are more sensitive to injected LPS than those with APOE3, and similarly mice with endogenous ApoE replaced with APOE4 are more sensitive to LPS than those replaced with APOE3 (Vitak et al. 2009; Gale et al. 2014), consistent with APOE4 being detrimental in AD by increasing LPS toxicity or decreasing LPS clearance. Here, APOE is linked to Alzheimer disease.