Furthermore, we provide the first evidence that plasma levels of IFN-γ, the IFN-γ/IL-10 ratio, IL-17F, and the IFN-γ/IL-17F ratio in a subgroup of patients, as well as the frequency of Th1 cells and the Th1/Th17 cell ratio, might represent relevant immunological markers useful for differentiating, monitoring, and potentially predicting the transition to specific MS stages. The gene discussed is IL17F; the disease is myeloid sarcoma.