CSF3 and cancer: However, in a cancer setting, the overproduction of soluble factors such as granulocyte macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), IL-6, VEGF and TNFα promotes the formation of MDSCs that are recruited to the tumour site via the CXC family of chemokines such as CCL2, CXCL-12, CXCL-15 [102].