MAPT and Alzheimer disease: New strategies based on biomarker detection have been explored in the last few years for AD diagnostics.[5, 7] As an example the Aβ42/Aβ40 ratio has proven to have a strong concordance with AD diagnosis and progression monitoring.[8] Not only the level of Aβ42, but also phosphorylated tau (p‐tau), and total tau (t‐tau) proteins start to change almost 10–15 years before the appearance of AD symptoms.[9]