While lack of BLIMP-1 gives defective cytolytic function in virus-specific CD8+ T cells and low expression of KLRG1 [77], the potential role of BLIMP-1 in the upregulation of multiple inhibitory molecules is clear in chronic viral infections, especially in LCMV and HIV-1 infection [2,4,63,103]. Here, PRDM1 is linked to HIV-1 infection.