It is also reported that CHI3L1 is up-regulated in patients with chronic neurological disease such as Alzheimer’s disease, bipolar disorder, and schizophrenia (Bonneh-Barkay et al., 2010; Choi et al., 2018; Sahin et al., 2019). Here, CHI3L1 is linked to early-onset autosomal dominant Alzheimer disease.