Mast cells promote tumor growth by releasing cytokines and growth factors, such as fibroblast growth factor (FGF)-2, vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), nerve growth factor (NGF), interleukin (IL)-8, and IL-10 (high expression), histamine through H1 receptors, tryptase and chymase. Here, NGF is linked to neoplasm.