Th17 and regulatory T (Treg) cells are twosubsets of CD4+T-cells which have critical functions in the onset and progression of MS.The current study seeks to distinguish fluctuations in expression of CD4+T-cell derivedmiR-223 during the relapsing-remitting (RR) phase of MS (RR-MS), as well as the expressions of Th17 and Treg cell markers. The gene discussed is CD4; the disease is myeloid sarcoma.