CHI3L1 and Alzheimer disease: Neurogranin is a postsynaptic protein and considered a soluble marker of synaptic integrity due to its involvement in memory function and synaptic plasticity, both showing early impairment in AD.10 Glial fibrillary acidic protein (GFAP), chitinase 3–like protein 1 (YKL-40), and soluble triggering receptor expressed on myeloid cells 2 (sTREM2) are further biomarkers of interest reflecting neuroinflammatory processes of astrocytes and microglia,11,12,13,14 whereas neurofilament light protein (NfL) is a nonspecific marker of axonal degeneration in AD.15