IFNGR1 and Splenomegaly: For example, we observed that splenomegaly persists in SAVI mice, regardless of which IFN receptor is deleted (Supplemental Figure 1B), and that survival of Ifngr1–/– SAVI mice may be only slightly improved (Supplemental Figure 1C), suggesting additional IFN-independent or combinatorial IFN receptor–dependent effects.