Activation-induced cell death is a specific term used for the apoptosis of T lymphocytes in the periphery. This process is of central importance in the homeostasis of the immune system. For example, an effective response to foreign invaders such as the powerful antigenic stimulus of bacterial super antigens is the extensive proliferation of T lymphocytes with a tremendous expansion of antigen specific T cell clones and efficient immune-mediated clearance of bacteria. This is followed by apoptosis of the majority of these antigen specific T cells, which serve to return the numbers of T cells in the periphery to normal.