APOE and atherosclerosis: The first evidence for atheroprotective functions of Treg cells was reported in mouse studies with either pharmacological depletion of Treg cells using anti-CD25 antibodies (86, 87) or temporal FoxP3-specific diphtheria toxin-targeted (FoxP3DTR) (88) depletion of Treg cells in mouse models for atherosclerosis, namely in apolipoprotein E–deficient (ApoE–/–) or low-density lipoprotein receptor–deficient (Ldlr–/–) mice.