Interestingly, elevated levels of CSF YKL-40 were observed in patients with dementia or mild cognitive impairment due to Alzheimer’s disease, although there was no correlation with core biomarkers such as t-tau and p-tau proteins and Aβ42 in Alzheimer’s disease patients [192]. The gene discussed is CHI3L1; the disease is early-onset autosomal dominant Alzheimer disease.