IL4 and neoplasm: It is well known that naïve helper T cells (Th0) can be transformed into Th1, Th2, Treg and Th17 cells etc. Th1 produces the cytokine interferon gamma (IFN-γ) that exerts anti-tumorigenic effects in the tumor microenvironment, while Th2/Treg produces the cytokines interleukin 4 (IL-4), IL-5, IL-10, etc. that mediate pro-tumorigenic effects (17).