CELSR3 and myeloid sarcoma: While most of the age-concordant proteins were proteins secreted to extracellular space and were part of the extracellular matrix, age-discordant CSF proteins (i.e., decreased in HV but increased in MS) belonged to two categories: Secreted proteins linked to immune system; and the cell surface/membrane-anchored proteins found in axons and the neuronal cell body (Fig. 2 and Supplementary Data 2).