Despite increased susceptibility of IFNγR-deficient mice to S. aureus infections [46] the role of CD8+ T cells, classical IFNγ-producers, has neither been investigated nor have infection models addressed the T cell response to intracellularly persisting S. aureus. This study provides proof for the existence of a human CD4+ and, more important in this context, a CD8+ T cell memory pool specific for S. aureus in healthy donors. This evidence concerns the gene CD4 and infection.