(A,B) Tumor cells were injected s.c. into WT, Stinggt/gt, or Cgas−/− mice (n=4-6). Analysis was as in Fig. 1 legend. Results are representative of two independent experiments. Mice were injected with 2 × 105 RMA-S cells (A) or 2 × 104 B16-BL6 cells (B). (C,D) Splenocytes from WT, Stinggt/gt or Cgas−/− mice were transfected with either Vaccinia Virus dsDNA 70mer (C), or 2'3'-cGAMP (D), and secreted type I IFN in culture supernatants was measured using an IFN bioassay. Splenocytes from WT or Cgas−/− mice (n=6) were analyzed by flow cytometry for the absolute number (E) or percentage (F) of NK cells, or the percentages of NK cells expressing CD11b (G) or Ly6C (H). Results are representative of two to four independent experiments. Bars represent means +/− SEM. Statistical significance was assessed using 2-tailed t tests (E-H) or 1-way-ANOVA with Bonferroni’s correction for multiple comparisons (C-D).