PTGS2 and neoplasm: Extensive investigations have confirmed that tumor growth and metastasis depend on angiogenesis, and multiple angiogenic factors such as vascular endothelial growth factor (VEGF), bFGF, TGF-β1, MMP, cyclooxygenase-2 (COX-2), CD34, and c-KIT are associated with the prognosis of sarcoma [23].