MMP9 and myeloid sarcoma: All together, these markers will reflect inflammatory pathways (e.g., PTX3, OPG, sTNF-R1, IL-1Ra and CXCL16), the interaction between leukocytes and endothelial cells (e.g., PTX3, ALCAM, CXCL16 and CCL21) and extracellular matrix remodeling (e.g., OPN, OPG, TGFβ and MMP-9), all processes with relevance for the pathogenesis of MS.