CCR4 and primary progressive multiple sclerosis: However, CCR5+, CXCR3+, CCR6+ and CCR4+ cells within the CD4+ CD45RA− memory T-cell pool of the CSF of OCR-treated people with primary progressive multiple sclerosis were all depleted for CD20dim T cells, which was not the case for the CD8+ memory T-cell pool (Supplementary Fig. 4).