CXCL13 and myeloid sarcoma: In contrast to healthy individuals, over-secretion of T helper 1 (Th1) and proinflammatory cytokines leads to imbalanced serum levels of tumor necrosis factor (TNF-α), interferon-gamma (IFN-γ), interleukin (IL)-1, IL-2, IL-12, IL-15, IL-6, chemokine (C–X–C motif) ligand 8 (CXCL8) and CXCL13, chemokine (C–C motif) ligand 20 (CCL20), T helper 2 (Th2) and anti-inflammatory cytokines IL-4, IL-5, IL-10, and IL-13 in MS patients [7,15].