MAPT and Alzheimer disease: Additionally, participants with very mild/mild dementia exhibited the typical AD CSF biomarker profile characterized by significantly lower mean levels of CSF Aβ42 and higher mean levels of CSF tau and CSF p-tau181, as well as displaying higher mean cortical amyloid burden (MCBP assessed by PIB-PET imaging) as has been seen previously (Tables 1 and 2) [6], [31], [32].