IL4 and neoplasm: The TME usually has high levels of IL-4, which contributes to immunosuppression by inducing polarization of Th2 cells and M2 macrophages while inhibiting Th1 cell polarization and proinflammatory cytokine production by antigen-presenting cells (APCs).41 In some tumor types, IL-4 directly promotes tumor growth.42 In order to overcome these inhibitory signals, Wilkie et al developed a chimeric IL-4 receptor called 4αβ, which contains the IL-4Rα ectodomain (AA1-233) fused to the transmembrane and intracellular domain of IL-2Rβ (AA241-551).