The expression of miR-27b and miR-128 is increased in naïve CD4 + T lymphocytes, and miR-340 expression is increased in memory CD4 + T lymphocytes in MS patients; these increased miRNAs contribute to the proinflammatory Th1 response by inhibiting the expression of IL-4 and B lymphoma Mo-MLV insertion region 1 homolog (BMI1). Here, BMI1 is linked to myeloid sarcoma.