The overall aims of the current study were: 1) to investigate the binding properties of a first-generation and a second-generation Tau tracer compared to a commonly used amyloid tracer in DS and AD tissue, and 2) to examine regional differences in Tau and amyloid binding in DS-AD and DS-MCI tissue versus early onset (EOAD) and late onset (LOAD) AD tissue. Here, MAPT is linked to Alzheimer disease.