Interestingly, CD8+ IFNγ-/- T cells were revealed to be less efficient than CD8+ Perforin-/- T cells to keep persisting R. typhi below the qPCR detection limit in this infection model [49,50], suggesting that the production of IFNγ by CD8+ T cells is more important than the cytotoxic activity for long-term control of the bacteria. Here, PRF1 is linked to infection.