ApoE is involved in the pathogenesis of infectious diseases as well as susceptibility to pathogens, including herpes simplex virus-1 (HSV-1), hepatitis C virus (HCV), hepatitis E virus (HEV), HIV-1, varicella zoster virus (VZV), and Epstein-Barr virus (EBV), malaria, Listeria monocytogenes (LM), and Klebsiella pneumoniae [51–66]. Here, APOE is linked to infectious disease.