For instance, a study depleting regulatory CD4+ T cells (Tregs) in the amyloid 5xFAD mouse model demonstrated a reduction in pathology,28 whereas another study involving Treg depletion in the 3xTg‐AD mouse model reported increased Aβ plaques in the hippocampus associated with a marked aggravation of the spatial learning deficits of the treated mice.29 This evidence concerns the gene CD4 and Alzheimer disease.