Experimental autoimmune encephalomyelitis (EAE), the animal model of MS, can be induced by immunization with autoantigen, which activates Th1 (25) and Th17 (26) effector responses, but a Th2 response is also induced and produces IL-4, IL-5, and IL-13 (25, 27, 28). This evidence concerns the gene IL5 and experimental autoimmune encephalomyelitis.