IL21 and myeloid sarcoma: Recently, it has been demonstrated that the Foxp3 expression from CD4+CD25- T-cell pool of MS patients was inversely correlated with the production of IFN-γ, IL-6, IL-21 and IL-17 and also IL-6 neutralization of the culture of PBMC from MS patients markedly enhanced the expression of FoxP3 in FoxP3low T-cell clones[54] ,therefore, our observation can be interpreted in light of the inflammatory nature of MS.