IGHE and neoplasm: In summary, crosslinking IgE antibodies on the surface of human macrophages influenced their polarisation status (Fig. 7), leading quiescent macrophages to acquire M1-like features, M1 macrophages to retain their pro-inflammatory status and skewing differentiated M2 macrophages towards a pro-inflammatory phenotype, with measurable anti-tumour activity when tumour antigen-specific IgE could target macrophages against cancer cells.