219 these cells: short-lived plasma cells and longlived plasma cells1. Short-lived plasma cells are generated within a few days after infection and die after 2 weeks. The antibodies secreted by short-lived plasma cells help to control the infection. Meanwhile, long-lived plasma cells, which are generated through the germinal-center pathway, migrate and take up residence in the bone marrow and P cells, which are terminally differentiated B cells, are the workhorses of humoral immunity. There are two types of the foreign antigen–driven IL-2 response of a T cell is preordained by the avidity of its TCR for self peptide–MHC; higher avidity for self molecules correlates with more robust immediate IL-2 production4. What role is served by the enhanced IL-2 response? It is conceivable that the CD5hi T cells participate in the initiation of the immune response by producing copious IL-2 and, having filled that role, die. Alternatively, instead of being their raison d’être, the enhanced IL-2 production of CD5hi T cells may simply represent an autocrine aspect of their preassigned ‘suicide program’. Curiously, not all LLO56 cells die during primary infection, and the population expansion of LLO56 cells actually outstrips that of LLO118 cells in the secondary response8. What causes this reversal of fates? In addition to defining the prevalence of naive T cells with the peculiar activation program of LLO56, future research should delve into the importance of these characteristics in terms of host health.