To further dissect whether T-cell activation in secondary lymphoid organs or recruitment into the infarcted heart were responsible for the reduced numbers of CD4+ T-cells in the heart after MI we studied the impact of the anti-CD28 antibody treatment on the CD4+ T-cell compartment in heart draining lymph nodes as the T-cell activation process in response to MI mainly takes place there [20]. The gene discussed is CD4; the disease is myocardial infarction.