To address whether the acquisition of typical features of Th17 cells were differentially modulated in MS patients compared to healthy donors, we analysed the expression of the transcription factor ROR-γt, a master regulator of both mouse [12] and human Th17 cell differentiation [11,22], CCR6 [23] and IL-1R1 [15], which are not found in Th1 and Th2 cells, and are considered hallmarks of Th17 cells. This evidence concerns the gene CCR6 and myeloid sarcoma.