The objective of this work was threefold 1) to test if monomeric IgE (in the absence of antigen) could induce the production of VEGF in MC in vitro; 2) to analyze if monomeric IgE could exacerbate the pro-tumorigenic properties of this cell type in vivo; and 3) to investigate some of the molecular mechanisms underlying the effects of IgE on VEGF production and tumor growth. This evidence concerns the gene IGHE and neoplasm.