GFAP and Parkinson disease: The glial activation biomarkers YKL-40 (chitinase-3-like protein 1) and MCP-1 (monocyte chemoattractant protein-1) are increased even further in atypical parkinsonian patients compared with PD and can thus reliably discriminate tauopathies from synucleinopathies,149,150 although this is best achieved by combining them with a panel of non-inflammatory CSF biomarkers [area under the curve (AUC) = 0.95].151 Among PD patients, GFAP levels seem to predict the development of dementia.152