To investigate if the other CXCR3 ligand, CXCL10, or the receptor itself are contributing to murine FHL, we treated prf1−/− mice infected with LCMV to induce FHL with a CXCR3 antagonist, AMG487, starting at day 3 post infection (p.i). Here, PRF1 is linked to hemophagocytic syndrome.