Although the exact mechanism has not yet been defined, studies have shown that this process is highly correlated with the formation of tumor-associated mesenchymal stem cells, granulocyte macrophage colony-stimulating factor (GM-CSF), and polymorphonuclear myeloid-derived suppressor cells, which lead to alterations in immune cell responses and relevant signaling pathways [14–18]. Here, CSF2 is linked to neoplasm.