MAPT and early-onset autosomal dominant Alzheimer disease: Understanding the key physiological brain mechanisms that protect the foetal brain from phosphorylated tau-related pathology may offer insights into therapeutic strategies to prevent or reverse tau pathology in neurodegenerative diseases.4,11 Here, we aim to investigate phosphorylated tau in newborns and Alzheimer’s disease by comparing levels of blood-based p-tau217 in different age groups and Alzheimer’s disease.