BIRC5 and nasopharyngeal carcinoma: In summary, these findings suggest that positive expression of β-catenin, TCF-4, and survivin proteins is independent risk factors for OS and DFS of NPC prognosis, while clinicopathological stages and TCF-4 and EBV-EA-IgA are significantly related to OS, DMFS, LRFS, and DFS of NPC.