SPP1 and neoplasm: The effects of these can be divided into three categories: The first group of molecules stimulate the pleural inflammation (e.g., interleukin 2—IL2; tumor necrosis factor—TNF and interferon—INF); the second group of molecules stimulate tumor angiogenesis (e.g., angiopoietin 1 (ANG-1), angiopoietin 2 (AGN–2); the third group of molecules affect vascular hyperpermeability (e.g., vascular endothelial growth factor—VEGF, matrix metalloproteinases—MMP, chemokine (c-c motif) ligand 2—CCL, osteopontin—OPN, etc.)[1,19].