As March comes around, many people experience hay fever. As excessive immune responses go, most would admit that hay fever really isn’t that bad. At the other end of the spectrum are severely debilitating autoimmune diseases like rheumatoid arthritis and multiple sclerosis. A common thread in all these conditions are cytokines, molecules that cause inflammation. Recent research by the University of Tsukuba sheds light on the effect of excessive cytokines on neuronal and glial cells in the brain.