MAPT and Alzheimer disease: With the advances of available AD biomarkers in vivo, such as structural magnetic resonance imaging (MRI), molecular neuroimaging with positron emission tomography (PET), and cerebrospinal fluid (CSF) analysis of Aβ or tau proteins, the International Working Group (IWG) proposed a new conceptual framework for the diagnosis of AD in 2007, which highlighted the combination of clinical phenomenology and biological markers.39