PTGS2 and nasopharyngeal carcinoma: Promotion of metastasis in NPC is orchestrated by LMP1, which regulates a cascade of molecular signaling involving MMP-9, mucin 1 (MUC1), vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2), fibroblast growth factor 2 (FGF-2), and HIF-1α [39].