CXCL13 and myeloid sarcoma: Taking into consideration CSF analysis in relapsing forms of MS, there are multiple reports confirming the applicability of NfL, CXCL-13 and/or YKL-40 as predictive biomarkers of conversion to CDMS [84] and/or disability worsening [67,85,86,87] and/or a higher rate of disability accumulation [24].