When comparing protein profiles of plasma samples from LNB and viral meningitis, patients with LNB generally seem to have a relative upregulation of proteins associated with innate immunity and complement activation (e.g., FCN3, SERPING1, SERPINA5), lipid metabolism (e.g., APOE, APOC1, APOM), and coagulation regulation (e.g., F13A1, PROC). Here, APOE is linked to viral meningitis.