CSF2 and neoplasm: The expression of inflammatory mediators, such as IL-1β, IL-6, prostaglandin E2 (PGE2), granulocyte macrophage colony-stimulating factor (GM-CSF), and vascular endothelial growth factor (VEGF), is increased in the tumor microenvironment, thus recruiting MDSCs in the plasma to the site of inflammation and inducing their activation.