MAPT and Alzheimer disease: Assuming the crucial role of biomarkers to characterize preclinical AD cases and trying to shed light on the debate between the cognitive phenotype and the preclinical/prodromal hypotheses, we combined here APOE4 genotype and neuropsychological assessments with Aβ markers derived from PET scanning and CSF analysis, as well as with FDG-PET, hippocampal volumetry, and Tau markers.