CHI3L1 and in situ carcinoma: This fact should be taken into account, as there is evidence that systemic levels of CHI3L1 can increase in a variety of non-neurological pathologies [69].The study with the longer follow-up (median, 11.7 years) in a cohort of 301 patients with RRMS and CIS showed that elevated levels of CHI3L1 at disease onset independently predicted a shorter time to reach irreversible EDSS score of 3 and 6 [34].