A flowchart illustrating the potential mechanisms underlying cognitive and mood dysfunction, fatigue, neuronal hyperexcitability, and neuroinflammation in Gulf War Illness (GWI) as observed from studies on the brain, cerebrospinal fluid, and the blood from veterans with GWI. CAMKII, calcium-calmodulin kinase II; GFAP, glial fibrillary acidic protein; HLA, human leukocyte antigen; MAP2, microtubule-associated protein-2; MBP, myelin basic protein; tau, microtubule-associated tau (T) proteins.