SYP and Alzheimer disease: Second, patients received diagnoses based on established clinical criteria only,37,38 without testing for ATN biomarkers in AD such as the deposition of amyloid-β and tau proteins established via Positron Emission Tomography, CSF, or plasma in AD.94, 95, 96, 97 Further, biomarkers relevant for bvFTD, such as neurofilament light chain in CSF and synaptic proteins such as Synaptophysin and GAP4398, 99, 100 were not available.