CSF2 and neoplasm: It has been demonstrated that MDSCs-derived exosomes contain matrix metalloproteinases (MMPs) and different cytokines, chemokines, and growth factors (CSF, VEGF, MCP, SDF1α, TNFα, and IFNγ), which establish a pro-metastatic microenvironment that allows the metastatic progression of tumor cells (Umansky et al., 2016).