While interferon-γ (IFN-γ)-associated Th1 and interleukin-17 (IL-17)-associated Th17 cells are considered to lead to disease progression and worsening of symptoms, IL-4-associated Th2 and transforming growth factor-β (TGF-β)-associated Treg have been indicated to associate with inflammation reduction and improvement of symptoms in MS patients [69]. The gene discussed is IL17A; the disease is myeloid sarcoma.