Simple blood-based biomarkers that correlate biochemical changes to clinical or cognitive status, when used in conjunction with genetic risk status, may increase the power of predicting who will decline in an asymptomatic population. An additional aspect of this protocol is to obtain blood based biomarker information to identify differences in markers of CTE sufferers. Better characterizing the relationship between various biochemical markers and disease status may allow us to improve our understanding of CTE causes, enhance our ability to diagnose early, and may lead to more effective treatments in the future. Researchers propose investigating several blood-based biomarkers related to inflammation, (Interleukin (IL)-1, I-309, IL-6, IL-13, and superoxide dismutase 3; SOD3) in diseased (clinical diagnosis of AD) and healthy APOE e3 and APOE e4 carrying individuals to better characterize inflammation levels in these genetic groups.