To assess the antitumor effects of cGAMP against solid tumors within the BM, bone-metastatic 4T1-592 mammary carcinoma cells were injected into the tibiae of 6 to 8 weeks old female Balb/c mice and treated with cGAMP encapsulated in STING-NPs or PBS vehicle (untreated) by tail vein injection (Fig. 1A and B). Here, STING1 is linked to breast carcinoma.