S100A9 and nasopharyngeal carcinoma: To study the association of Annexin A1, Vimentin and S100A9 with the NPC cells invasion ability, high metastatic 5-8F cells were immediately transfected with the GV146-ANXA1 plasmid and GV146-ANXA1-negative control plasmid and established the cell lines 5-8F-ANXA1(+) and 5-8F-ANXA1(−), respectively; non-metastatic 6-10B cells were immediately transfected with ANXA1-RNAi plasmid and ANXA1-RNAi-negative control plasmmid and established the cell lines 6-10B-siRNA(+) and 6-10B-siRNA(−), respectively.