MS4A1 and myeloid sarcoma: The correlation between CSF concentration of MBP and CSF prevalence of the CD8+CD20+ subpopulation was confirmed in a PP-MS cohort (p = 0.0005; rs = 0.53), where no significant correlations were observed with CD4+CD20+ (p = 0.51; rs = 0.11), total CD4+ (p = 0.12; rs = 0.25), and CD8+ T cells (p = 0.13; rs = 0.25), nor between CSF neurofilament light chains (NFL) concentrations and CD4+CD20+ (p = 0.33; rs = 0.17) or CD8+CD20+ frequencies (p = 0.057; rs = 0.32) [32].