Researchers have found that a protein that regulates white blood cells in the human brain could protect against Alzheimer's disease. The results published in the journal Communications Biology suggest that this protein called CD33 could have important implications in the fight against Alzheimer's disease. Immune cells in the brain called microglia play a critical role in Alzheimer's disease explained study co-author Matthew Macauley Assistant Professor at University of Alberta in Edmonton Canada. They can be harmful or protective. Swaying microglia from a harmful to protective state could be the key to treating the disease Macauley added. Scientists have identified the CD33