One line of evidence that these immune mediators are operatives in MS is the marked decline in CSF concentrations of CKs (CXCL9, CXCL10, CXCL11, and CCL22) and other cytokines (IL-1β, IL-6, and IL-8) following natalizumab treatment (123). The gene discussed is CXCL8; the disease is myeloid sarcoma.