Similarly, tumour-infiltrating MDSCs have also been found to express heightened levels of the IL-4 and IL-13 receptors [28], and while antibody-mediated blockade of the IL-4 and IL-13 pathways are promising and actively explored in ongoing clinical trials [54], these cytokines have pleiotropic effects and non-specific blockade may lead to unwanted side effects. This evidence concerns the gene IL4 and neoplasm.