Similar findings were observed in patients with multiple sclerosis with rapid neurological deterioration, which displayed higher CSF CHIT1 levels in addition to other markers of microglial activity, such as TREM-2 (triggering receptor expressed on myeloid cells 2) and CH3L1 (chitinase-3-like protein 1 precursor) (41). Here, CHIT1 is linked to multiple sclerosis.