Apolipoprotein E (APOE)

APOE (Apolipoprotein E) is a protein encoded by the APOE gene on chromosome 19 that plays a key role in helping transport lipids (fats) like cholesterol throughout the body. It is produced mainly in the liver and brain, and it’s involved in the metabolism of fats by helping them get to the cells that need them. APOE is also important for brain health, as it helps repair damaged nerve cells and supports the function of brain cells. There are different versions of the APOE gene, called alleles, with the most common being APOE ε2, APOE ε3, and APOE ε4. The APOE ε4 allele is linked to an increased risk of Alzheimer’s disease, while APOE ε2 may offer some protection. How APOE works and how its different forms affect health are areas of active research.