Similar results were obtained for the second validation cohort (cohort 3, Additional file 2), where YKL-40 levels in sCJD were significantly higher (603 ± 198 pg/mL) than those detected in cognitive impairment/dementia cases (358 ± 129 pg/mL, p < 0.01) (Fig. 8b, cohort 3 Additional file 2). This evidence concerns the gene CHI3L1 and Cognitive impairment.