When incorporated into a panel alongside established MS biomarkers (CXCL13 ratio, neopterin ratio, CSF level of neurofilament light polypeptide, IgG index, and serum level of osteopontin) it improved the diagnostic specificity for differentiating MS patients from symptomatic controls and revealed unique profiles for each subtype of MS (72). Here, SPP1 is linked to myeloid sarcoma.