CHIT1 and amyotrophic lateral sclerosis: The mean CHIT-1 level in the N-CSF was 1144 ± 763.30 pg/ml (n = 48) and in NALS-CSF was 909.4 ± 934.43 pg/ml (n = 12) whereas in the ALS-CSF the mean was 22,015 ± 25,804 pg/ml (n = 158) (Fig. 1a).