For this reason, recent research focused on the microglial activation markers chitinase-3-like protein 1 (YKL40), monocyte chemotactic protein 1 (MCP1), visinin-like protein-1 (VILIP1), and glial fibrillary acidic protein (GFAP) has found them to be upregulated in the cerebrospinal fluids (CSF) of AD patients [84]. Here, CHI3L1 is linked to Alzheimer disease.