These stratified analyses revealed highly similar results compared to the original models with an interaction term: in CU Aβ-positive participants, WML volume was associated with increased baseline tau load, microbleeds were associated with both increased baseline tau load and longitudinal tau accumulation, and stroke-related events were associated with decreased longitudinal tau accumulation (all adjusted for age, sex, APOE ɛ4 carriership and Aβ-PET SUVr). This evidence concerns the gene APOE and stroke disorder.