MAPT and Alzheimer disease: Taken together, the observed significant associations between KL-VSHET+ status and biomarkers for brain amyloidosis (CSF Aβ positivity) and tau pathology (CSF Tau and pTau negativity) are suggestive of neuroprotective effect of KL-VSHET+ against age-related biomarker, biomolecular, and cognitive alterations that confer risk for AD.