CHI3L1 and myeloid sarcoma: The median CSF levels of CHI3L1 were 133 ng/ml (93, 215) in MS patients and 58 ng/ml (47, 77) in non-MS controls (p < 0.001), and differed between MS phenotypes being 119 ng/ml (81, 186) in RRMS, 139 ng/ml (95, 211) in SPMS, and 180 ng/ml (146, 265) in PPMS (p = 0.01) (Table 1; Figure 2A).