We activated the STING signaling pathway in the tumor tissue using MnO2 NPs to promote the secretion of type I interferons [22–26], driving neutrophil repolarization toward the N1 phenotype (Scheme 1); this reshapes the tumor immune microenvironment, enhances the anti-tumor immune response, significantly improves the survival rate of tumor-bearing mice, and demonstrates good biological safety. This evidence concerns the gene STING1 and neoplasm.