CCR6 and myeloid sarcoma: There was a significant increase in the CSF of persons with MS for the CCR6+IL-17−IFNγ−GM-CSF+ CD4+ T cell subset, both for percentage and frequency (Fig. 4D), as well as for the equivalent CCR6− population (Fig. 4E), although again elevated in absolute numbers in both cohorts (Fig. 4I-J).