SPP1 and neoplasm: Growth factors derived from mast cells that can promote tumour development and angiogenesis include fibroblast growth factor (FGF)-2, tryptase, chymase, osteopontin and nerve growth factor (NGF), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), interleukin (IL)-8 and IL-10 (high expression) (angiogenesis and tumor growth), and histamine through H1 receptors.