APOE and Cognitive impairment: Although established dementia biomarkers, like FDG-PET, PIB ratio, cortical thickness, beta amyloid and APOE4, are widely used as risk markers for cognitive impairment, decline, and dementia, contradictory evidence that they do not predict global or future cognitive functioning, change, or decline, call into question their robustness in predicting dementia among older adults (10).