In most prodromal AD trials, amyloid-positive individuals are matched on APOE ε4 status, age, sex, and level of education, which are known to be associated with rate of disease progression.4,5,18, –, 20,27 We also found that abnormal tau levels are associated with steeper decline at group level, as also suggested by previous studies.4,19 One strategy to overcome the problem of heterogeneity might thus be to further select on risk factors that are associated with rate of decline. This evidence concerns the gene APOE and Alzheimer disease.