While the developmentof anti-TNF therapy has undoubtedly revolutionized the treatment ofdiseases such as rheumatoid arthritis and inflammatory bowel disease,5 these therapies can exacerbate neuroinflammatorydiseases of the central nervous system (CNS), such as multiple sclerosis.6−8 Despite its clear role in neuroinflammation, the precise effectof TNF on the cellular metabolism within the brain remains poorlyunderstood. The gene discussed is TNF; the disease is rheumatoid arthritis.