MAPT and Alzheimer disease: Support for this theoretical framework comes from a number of lines of evidence, including a variety of data-driven modelling approaches based on biomarker data.6-10 In an attempt to operationalize this, a simplified ATN model has been proposed.11 The components of the ATN model refer to the status of three different key biomarkers in Alzheimer’s disease: amyloid (A), tau (T) and neurodegeneration (N).