In addition to the promotion of angiogenesis, the activated mast cells are a rich source of cytokines and chemokines such as IL-1, IL-3, IL-4, IL-8, granulocyte–macrophage colony-stimulating factor, TNFα, interferon-γ (IFNγ), CCL-2, Macrophage Inflammatory Protein MIP-1α and β, many of which can contribute to the tumour microenvironment by enhancing tumour cell growth and invasion either directly or through intermediaries such as macrophages (Burd et al, 1989; Selvan et al, 1994). This evidence concerns the gene IL4 and neoplasm.