For example, increased C–C motif chemokine ligand 2 (CCL2) expression at the tumour site as a consequence of the accumulation of MDSCs in colorectal cancer tissues, at least in part [21], may lead to an elevation of type-2 immune response and thus, in theory, an elevation in the levels of IL-4 and IL-13 would be expected. Here, IL13 is linked to colorectal cancer.