In non-demented subjects with cognitive complaints, individual probability of conversion to AD has been assessed by a model combining plasma p-tau, apolipoprotein E (APOE) ε4 genotype, and simple executive (animal fluency and trail making test part B) and memory (Alzheimer’s Disease Assessment Scale–Cognitive Subscale memory subtests) tests. The gene discussed is APOE; the disease is early-onset autosomal dominant Alzheimer disease.