The primary focus of my lab is to investigate the relationship between APOE genotype and late onset Alzheimer’s disease (AD). The single most common and influential gene in AD is the APOE gene. The APOE gene is polymorphic; encoding three different alleles designated APOE2, E3 or E4. APOE4 carriers have the highest risk for AD while APOE3 carriers have an essentially neutral risk and APOE2 carriers may be protected against AD. The APOE4 gene is also linked to increased risk for atherosclerosis, cerebral amyloid angiopathy, peripheral neuropathy, multiple sclerosis, stroke and type II diabetes; as well as an increased susceptibility to HIV and Chlamydia infections, head injury and cognitive decline following coronary bypass surgery. The fact that 28% of the US population are carriers of the APOE4 gene, underscores the need for a better understanding of APOE’s relationship to disease. The major challenge facing researchers today is determining why some APOE4 carriers succumb to disease while others do not. Genetic modifiers and environmental risk factors likely explain different individual outcomes. The primary environmental risk factors are thought to be; a Westernized diet, low physical activity, chronic stress, poor sleep habits, andro/menopause and most importantly, age.