SPP1 and neoplasm: Among inflammatory cells found in tumor microenvironment, tumor associated macrophages and mast cells support tumor growth and neovascularization by production of a wide variety of angiogenic cytokines, including tumor necrosis factor alpha (TNF-α), TGF-β1, FGF-2, vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF), interleukin-8 (IL-8), osteopontin and nerve growth factor (NGF).