Both <i>in vitro</i>/<i>vivo</i> results indicate that BM@M<sub>FC</sub>C have excellent performance to inhibit primary/metastatic tumors, while single-cell RNA sequencing elucidates BM@M<sub>FC</sub>C can induce immunosuppressive TME remodeling, including increased CD8<sup>+</sup> T cells, cDCs, and NK cells; M2-to-M1 macrophage polarization; and enhanced intercellular communication. This evidence concerns the gene CD8A and metastatic neoplasm.