Alzheimer’s disease is the most common neurodegenerative disorder causing dementia in older people. With Alzheimer’s, brain cells shrink or disappear and are replaced by irregularly shaped spots or plaques. The amyloid beta (A-beta) protein is a central component of these plaques. A-beta is a normal part of brain cells, but is toxic in high concentrations. Dr. Yigang Tong is studying why there is an increase in A-beta proteins with some older people. He is focusing on the role of the BACE enzyme that produces this protein because he believes degradation of this enzyme is impaired, allowing the amount of A-beta to increase in brain cells. Identifying the steps involved in the degradation of the BACE enzyme could help explain how Alzheimer’s disease develops and potentially lead to new drugs to treat the condition.