Induction of eomesodermin-positive CD4<sup>+</sup> T cells (Eomes<sup>+</sup> T helper [Th] cells) has recently been correlated with the transition from an acute stage to a later stage of experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis.
Accordingly, our recent comparative analysis between MS and its animal model, experimental autoimmune encephalomyelitis (EAE), raises a new possibility that ectopic expression of eomesodermin (Eomes) in helper T (Th) cells constitutes a previously unappreciated subset of Th cells with cytotoxic potential against neuronal cells.