Multi-color flow cytometry was used to analyze the co-expression of CCR4 with CLA or CXCR3 on memory T cells in paired blood and CSF samples from an individual patient with a non-inflammatory neurological disease (A-D) or MS (E-F). The expression of trafficking determinants was analyzed on CD4+/CD45RO+ memory T cells to account for the different percentages of naïve and memory CD4+ cells in blood (A) and CSF (B). As expected, there was an association between the expression of CCR4 and CLA on CD4+/CD45RO+ T cells in peripheral blood (C). A majority of CLA+ memory T cells co-expressed CCR4 also in the CSF, but some CCR4 staining could be detected on CLA- memory T cells (D). While a large population of CCR4+/CXCR3- cells, which have been demonstrated to be enriched for Th2 cells , were present in peripheral blood (E), such cells were rare in the CSF (F).