NEFL and Alzheimer disease: More recently neurofilament light (NfL),21 neurogranin,22, 23 and chitinase‐3‐like protein 1 (CHI3L1, also known as YKL‐40)24 have also shown utility as CSF biomarkers for neurodegeneration, neuroinflammation, or synaptic damage in AD and other neurodegenerative diseases, and they are thus becoming more routinely measured in a research context.