IGHE and neoplasm: In parallel, we detected TNFα‐expressing macrophage subsets and elevated concentrations of TNFα in lung metastases of IgE‐treated rats.11 Consistent with these, here IgE treatment enhanced immune cell recruitment in rat lung tumours, and activation of immunological pathways in tumour‐bearing lungs, alongside elevated TNFα in the sera of IgE‐treated rats compared with controls.