STING-triggered tumor-migrating macrophages participated in the anti-tumor effects of STING-activating compounds.Intratumoral injections of cGAMP significantly delayed tumor growth in CD8+ T cells and STING signaling-dependent way. CD45+CD11bmid Ly6C+MHC class II+ macrophages that produced TNF-α and T cell-recruiting chemokines transiently accumulated in mouse tumor microenvironment after intertumoral injection of cGAMP to perform anti-tumor effect. This evidence concerns the gene STING1 and neoplasm.