MAPT and Alzheimer disease: In individuals with mild cognitive impairment and mild dementia due to early onset AD, females exhibit significantly higher cerebrospinal fluid (CSF) total tau and phosphorylated tau levels than males in the setting of similar cognitive abilities,8 and females with autosomal dominant forms of AD also showed a steeper increase in plasma neurofilament light chain (NfL) with disease progression (proxied by age).9