These individuals would either still have sufficient tau pathology to qualify for AD but we cannot detect it because of the limited sensitivity of tau PET to detect early tau pathology (i.e., false negative cases that could represent AD), or other pathologies could have been present contributing to cognitive decline by acting synergistically or additively to Aβ pathology [11, 46, 55, 56]. The gene discussed is MAPT; the disease is Alzheimer disease.