Moreover, APOE ε4 appeared beneficial in certain infectious diseases evoked by both viruses (e.g., hepatitis C, HCV) and bacteria (e.g., malaria) [131–133], though, on the contrary seemed rather detrimental in the case of human immunodeficiency virus (HIV) and herpes simplex virus (HSV) infections [134, 135] (reviewed in [136]). This evidence concerns the gene APOE and infectious disease.