IL13 and neoplasm: It has been proposed that exposure to the tumour cells and to additional tumour-derived molecules such as IL-4, IL-10, IL-13, TGFβ-1 (transforming growth factor - β) and PGE2 (Prostaglandin E2) initiates the development of TAMs, as well as initiating the development of characteristics akin to those of the M2 macrophages [3,6].