This paradox was apparently resolved when an alternative lineage of myelin-reactive CD4+ T cells, which produce IL-17A as their signature cytokine (Th17 cells), was detected in the draining lymph nodes of wildtype (WT) mice with EAE, as well as in the PBMCs, cerebrospinal fluid, and CNS infiltrates of patients with MS [59,60]. This evidence concerns the gene IL17A and myeloid sarcoma.