PSEN1 and Alzheimer disease: Using 5xFAD mice, which express human amyloid precursor protein (APP) and presenilin-1 (PSEN1) transgenes and recapitulate many AD-related phenotypes, they showed that peripheral injection of XPro1595 alleviated the age-dependent increase in activated immune cells in the brain of transgenic mice, decreased beta-amyloid plaque load, and rescued impaired long-term potentiation (LTP).