This was supported by three facts: (1) CD4+ T cells isolated from CNS from mice with EAE express detectable levels of IFN-γ messenger RNA (mRNA) [140]; (2) IL-12p40-defective (IL-12p40−/−) mice are resistant to EAE induction, because IL-12 is a requirement for naïve T cell differentiation in Th1 cells [141]; and (3) patients with MS exhibited exacerbation during treatment with IFN-γ [142]. The gene discussed is CD4; the disease is myeloid sarcoma.