IL4 and neoplasm: In view of (i) numerous in vitro and in vivo observations that monocytes and macrophages drive anti-tumour IgE functions [31,32,42]; (ii) the consistent absence of upregulation of type 2 cytokines, such as IL-4, in these models [32,67]; and (iii) elevation of molecules associated with type 1 immune responses, including IFN-γ, IL-12, TNFα, IL-6, CXCL11 and CCL5 following IgE cross-linking on MDMs [46], this axis more closely resembles an IgE-mediated parasiticidal response, rather than an IgE-mediated allergic profile [68,69].