We have found that osteopontin (OPN) is a proinflammatory molecule that is increased in the brain early after infection with WNV, as well as in other CNS pathologies, such as multiple sclerosis, experimental autoimmune encephalitis, experimental stroke, simian immunodeficiency virus (SIV), and Theiler's virus infections [6–11]. Here, SPP1 is linked to multiple sclerosis.