Pair-wise comparisons with Bonferroni corrections showed that baseline YKL-40 levels were higher in MCI and AD patients, compared with the cognitively normal individuals (mean (SE) 304 (16) and 288 (12) ng/ml vs. 231 (16) ng/ml, p = 0.03 and p = 0.006), as shown in Table 2. This evidence concerns the gene CHI3L1 and Alzheimer disease.