IL4 and neoplasm: Once in the TME, monocytes can differentiate into two different types of macrophages depending on the chemical composition at the tumor location, the M1-type macrophages are formed in the presence of interferon gamma (IFN-γ), and the M2-type macrophages when exposed to different interleukins (IL, e.g., IL-4 or IL-10), transforming growth factor beta (TGF-β), Granulocyte-macrophage colony stimulating factor (GM-CSF), annexin A1 or tumor cell-surface molecules (reviewed in Italiani and Boraschi, 2014; Goswami et al., 2017).