["Alzheimer's disease (AD) pathology appears several years before clinical symptoms, so identifying ways to detect individuals in the preclinical stage is imperative. The cerebrospinal fluid (CSF) Tau/Aβ", "We used linear regression to identify genetic loci associated with CSF YKL-40 levels in 379 individuals (80 cognitively impaired and 299 cognitively normal) from the Charles F and Joanne Knight Alzheimer's Disease Research Center. We tested correlations between YKL-40 and CSF Tau/Aβ", 'We found that genetic variants on the CH13L1 locus were significantly associated with CSF YKL-40 levels, but not AD risk, age at onset, or disease progression. The most significant variant is a reported expression quantitative trait locus for CHI3L1, the gene which encodes YKL-40, and explained 12.74\xa0% of the variance in CSF YKL-40 in our study. YKL-40 was positively correlated with ptau'] Does chitinase-3-like 1 protein ( CHI3L1 ) locus influence cerebrospinal fluid levels of YKL-40?