FGFb is an emerging MS biomarker with a controversial role in promoting myelination by oligodendrocytes [50–52], since the knockout mouse of FGFb in EAE showed that this growth factor has a neuroprotective/regenerative role avoiding nerve fiber degeneration and axonal loss and favoring remyelination in the CNS [53]. Here, FGF2 is linked to myeloid sarcoma.