IDO1 and infection: We found four major similarities in the action of the IRG system in defense against E. cuniculi: (1) the relocalisation of multiple IRG proteins to the cytosolic face of the PVM; (2) cooperativity by double-loading; (3) IFNγ- and infection- dependent host cell death and (4) IDO-independent IFNγ-mediated restriction in mouse cells.