CHI3L1 and Parkinson disease: In some studies, α-synuclein in the CSF has been found in samples of patients with AD or Parkinson’s disease and may be associated with other biochemical biomarkers.[12] Other biomarkers such as neurogranin, SNAP25, synaptotagmins, neuronal calcium sensing protein VLP1, YKL40 (CHI3L1), and soluble TREM2 have emerging[8] in recent years.