CD4 and myeloid sarcoma: The ability of myelin-reactive CD4 T cells to cause experimental autoimmune encephalomyelitis (EAE) further supports the hypothesis that myelin-reactive CD4 T cells have a central role in MS disease pathogenesis (Kuchroo et al., 2002; Sospedra and Martin, 2005; Ercolini and Miller, 2006; Hafler et al., 2007; Goverman, 2009; Steinman, 2009).