The innate myeloid lineage biomarker cluster (sCD14, sCD163, and CHI3L1; CSF cluster 1) correlated with ARMSS (Figure 5; ρ = 0.22, p = 0.012) and the T and memory B cell marker sCD27 correlated with both MS-DSS (ρ = 0.20, p = 0.014) and MSSS (ρ = 0.18, p = 0.044) in the whole MS cohort (Figure 5). Here, CHI3L1 is linked to myeloid sarcoma.