MMP9 and myeloid sarcoma: A very recent phase II randomized, double-blind, placebo-controlled clinical trial in progressive MS using intrathecally administered MSC-neural progenitors derived from bone marrow MSCs demonstrated increased MMP9 and decreased CCL2 levels in the CSF after treatment and potential benefit in a subgroup of pwMS.34 Of note, the measured outcomes of such approaches have been primarily based on the neuroprotective, rather than immunomodulatory, effects of MSCs.