To inhibit CCL2 and its cognate receptor CCR2 axis, Shen et al. synthesized siCCR2-encapsulated cationic nanoparticle (CNP/siCCR2) to inhibit primary tumor progression and further metastasis by reducing the abundance of TAMs and altering the immunosuppressive tumor microenvironment (Shen et al., 2018). Here, CCR2 is linked to neoplasm.