To determine whether cGAS inhibition could reverse the effect of PRMT3 inhibitor on tumor progression and T cell infiltration, we treated the Myc/Trp53−/− spontaneous model with a well-characterized cGAS inhibitor, RU.521, and found that RU.521 combined with SGC707 markedly reduced the anti-tumor activities of SGC707, led to bigger tumor volumes and weights (Fig. 7G, H) and a significant reduction in T cell infiltration (CD4+ T cells, CD8+ T cells, IFNγ+ CD8+ T cells, and GZMB+ CD8+ T cells) compared to the SGC707-treated group (Fig. 7I–L). Here, PRMT3 is linked to neoplasm.