MMP9 and nasopharyngeal carcinoma: To explore the mechanism of tumor suppression by RERG, we compared the expression levels of major ERK and NF-κB signaling pathway members, prominent cell migration and invasion molecules (MMP-2 and MMP-9), and several pro-angiogenesis-related factors, such as vascular endothelial growth factor (VEGF), IL8 and IL6 in NPC cells.