Increased T-regulatory cell function in the elderly balances increased autoimmunity but increases the incidence of cancer and sepsis. (A) Autoantibodies are frequent in aged individuals because of increased tissue damage and apoptosis. (B) Aiming to balance this increased autoimmunity, peripheral Tregs become enhanced, suppressing both CD4 and CD8 T cell function, allowing the development of cancers and increasing susceptibility to infections. (C) Recurrent viral and bacterial infections stimulate pro-inflammatory cytokines, which are further stimulated by this expansion of Tregs. (D) Treg expansion in the elderly is followed by the increase of T-helper 17 cells and the persistence of chronic inflammation.