APP and Alzheimer disease: This is demonstrated further by studies using IL-2 treatments to amplify Tregs, which have been shown in restore cognitive functions in APP/PS1 mice.60 However, there is a low presence of IL-2 in Alzheimer’s disease brains and Tregs are poor at producing IL-20.112,113 Taken together, this suggests that for Treg infusions to have long-term effects in Alzheimer’s disease, levels of IL-2 may also need to be increased within the CNS.