Classically, M1 polarization of macrophages can be obtained by stimulation with pathogen-derived LPS alone or in combination with Th1 cytokines, such as IFN-γ and GM-CSF, whereas IL-10, TGF-β, and PGE2 contribute toward the M2 phenotype and have been associated with a suppression of inflammation and anti-tumor activities.605. This evidence concerns the gene IFNG and neoplasm.