Supporting this, other studies demonstrated that amplification of Tregs restored cognitive function and delayed the onset of CD in mice models expressing chimeric mouse/human amyloid precursor and a mutant human presenilin 1 protein (APP/PS1).60‐63 Together, these studies suggest that Tregs are essential in learning and memory, which are key aspects of Alzheimer’s disease. Here, PSEN1 is linked to Cowden disease.